all: more linters (#24783)

This enables the following linters

- typecheck
- unused
- staticcheck
- bidichk
- durationcheck
- exportloopref
- gosec

WIth a few exceptions.

- We use a deprecated protobuf in trezor. I didn't want to mess with that, since I cannot meaningfully test any changes there.
- The deprecated TypeMux is used in a few places still, so the warning for it is silenced for now.
- Using string type in context.WithValue is apparently wrong, one should use a custom type, to prevent collisions between different places in the hierarchy of callers. That should be fixed at some point, but may require some attention.
- The warnings for using weak random generator are squashed, since we use a lot of random without need for cryptographic guarantees.

light/lightchain.go

@@ -355,22 +355,6 @@ func (lc *LightChain) Rollback(chain []common.Hash) {
 	}
 }
 
-// postChainEvents iterates over the events generated by a chain insertion and
-// posts them into the event feed.
-func (lc *LightChain) postChainEvents(events []interface{}) {
-	for _, event := range events {
-		switch ev := event.(type) {
-		case core.ChainEvent:
-			if lc.CurrentHeader().Hash() == ev.Hash {
-				lc.chainHeadFeed.Send(core.ChainHeadEvent{Block: ev.Block})
-			}
-			lc.chainFeed.Send(ev)
-		case core.ChainSideEvent:
-			lc.chainSideFeed.Send(ev)
-		}
-	}
-}
-
 func (lc *LightChain) InsertHeader(header *types.Header) error {
 	// Verify the header first before obtaining the lock
 	headers := []*types.Header{header}