build: upgrade to go 1.19 (#25726)

This changes the CI / release builds to use the latest Go version. It also
upgrades golangci-lint to a newer version compatible with Go 1.19.

In Go 1.19, godoc has gained official support for links and lists. The
syntax for code blocks in doc comments has changed and now requires a
leading tab character. gofmt adapts comments to the new syntax
automatically, so there are a lot of comment re-formatting changes in this
PR. We need to apply the new format in order to pass the CI lint stage with
Go 1.19.

With the linter upgrade, I have decided to disable 'gosec' - it produces
too many false-positive warnings. The 'deadcode' and 'varcheck' linters
have also been removed because golangci-lint warns about them being
unmaintained. 'unused' provides similar coverage and we already have it
enabled, so we don't lose much with this change.

rpc/doc.go

@@ -15,7 +15,6 @@
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
 /*
-
 Package rpc implements bi-directional JSON-RPC 2.0 on multiple transports.
 
 It provides access to the exported methods of an object across a network or other I/O
@@ -23,16 +22,16 @@ connection. After creating a server or client instance, objects can be registere
 them visible as 'services'. Exported methods that follow specific conventions can be
 called remotely. It also has support for the publish/subscribe pattern.
 
-RPC Methods
+# RPC Methods
 
 Methods that satisfy the following criteria are made available for remote access:
 
- - method must be exported
- - method returns 0, 1 (response or error) or 2 (response and error) values
+  - method must be exported
+  - method returns 0, 1 (response or error) or 2 (response and error) values
 
 An example method:
 
- func (s *CalcService) Add(a, b int) (int, error)
+	func (s *CalcService) Add(a, b int) (int, error)
 
 When the returned error isn't nil the returned integer is ignored and the error is sent
 back to the client. Otherwise the returned integer is sent back to the client.
@@ -41,7 +40,7 @@ Optional arguments are supported by accepting pointer values as arguments. E.g.
 to do the addition in an optional finite field we can accept a mod argument as pointer
 value.
 
- func (s *CalcService) Add(a, b int, mod *int) (int, error)
+	func (s *CalcService) Add(a, b int, mod *int) (int, error)
 
 This RPC method can be called with 2 integers and a null value as third argument. In that
 case the mod argument will be nil. Or it can be called with 3 integers, in that case mod
@@ -56,40 +55,40 @@ to the client out of order.
 
 An example server which uses the JSON codec:
 
- type CalculatorService struct {}
+	 type CalculatorService struct {}
 
- func (s *CalculatorService) Add(a, b int) int {
-	return a + b
- }
+	 func (s *CalculatorService) Add(a, b int) int {
+		return a + b
+	 }
 
- func (s *CalculatorService) Div(a, b int) (int, error) {
-	if b == 0 {
-		return 0, errors.New("divide by zero")
-	}
-	return a/b, nil
- }
+	 func (s *CalculatorService) Div(a, b int) (int, error) {
+		if b == 0 {
+			return 0, errors.New("divide by zero")
+		}
+		return a/b, nil
+	 }
 
- calculator := new(CalculatorService)
- server := NewServer()
- server.RegisterName("calculator", calculator)
- l, _ := net.ListenUnix("unix", &net.UnixAddr{Net: "unix", Name: "/tmp/calculator.sock"})
- server.ServeListener(l)
+	 calculator := new(CalculatorService)
+	 server := NewServer()
+	 server.RegisterName("calculator", calculator)
+	 l, _ := net.ListenUnix("unix", &net.UnixAddr{Net: "unix", Name: "/tmp/calculator.sock"})
+	 server.ServeListener(l)
 
-Subscriptions
+# Subscriptions
 
 The package also supports the publish subscribe pattern through the use of subscriptions.
 A method that is considered eligible for notifications must satisfy the following
 criteria:
 
- - method must be exported
- - first method argument type must be context.Context
- - method must have return types (rpc.Subscription, error)
+  - method must be exported
+  - first method argument type must be context.Context
+  - method must have return types (rpc.Subscription, error)
 
 An example method:
 
- func (s *BlockChainService) NewBlocks(ctx context.Context) (rpc.Subscription, error) {
- 	...
- }
+	func (s *BlockChainService) NewBlocks(ctx context.Context) (rpc.Subscription, error) {
+		...
+	}
 
 When the service containing the subscription method is registered to the server, for
 example under the "blockchain" namespace, a subscription is created by calling the
@@ -101,7 +100,7 @@ the client and server. The server will close the connection for any write error.
 
 For more information about subscriptions, see https://github.com/ethereum/go-ethereum/wiki/RPC-PUB-SUB.
 
-Reverse Calls
+# Reverse Calls
 
 In any method handler, an instance of rpc.Client can be accessed through the
 ClientFromContext method. Using this client instance, server-to-client method calls can be

rpc/handler.go

@@ -34,20 +34,20 @@ import (
 //
 // The entry points for incoming messages are:
 //
-//    h.handleMsg(message)
-//    h.handleBatch(message)
+//	h.handleMsg(message)
+//	h.handleBatch(message)
 //
 // Outgoing calls use the requestOp struct. Register the request before sending it
 // on the connection:
 //
-//    op := &requestOp{ids: ...}
-//    h.addRequestOp(op)
+//	op := &requestOp{ids: ...}
+//	h.addRequestOp(op)
 //
 // Now send the request, then wait for the reply to be delivered through handleMsg:
 //
-//    if err := op.wait(...); err != nil {
-//        h.removeRequestOp(op) // timeout, etc.
-//    }
+//	if err := op.wait(...); err != nil {
+//		h.removeRequestOp(op) // timeout, etc.
+//	}
 type handler struct {
 	reg            *serviceRegistry
 	unsubscribeCb  *callback