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.

tests/fuzzers/difficulty/difficulty-fuzz.go

@@ -30,7 +30,6 @@ import (
 type fuzzer struct {
 	input     io.Reader
 	exhausted bool
-	debugging bool
 }
 
 func (f *fuzzer) read(size int) []byte {

tests/init_test.go

@@ -116,6 +116,7 @@ func (tm *testMatcher) skipLoad(pattern string) {
 }
 
 // fails adds an expected failure for tests matching the pattern.
+//nolint:unused
 func (tm *testMatcher) fails(pattern string, reason string) {
 	if reason == "" {
 		panic("empty fail reason")

tests/rlp_test_util.go

@@ -124,7 +124,7 @@ func translateJSON(v interface{}) interface{} {
 func checkDecodeFromJSON(s *rlp.Stream, exp interface{}) error {
 	switch exp := exp.(type) {
 	case uint64:
-		i, err := s.Uint()
+		i, err := s.Uint64()
 		if err != nil {
 			return addStack("Uint", exp, err)
 		}

tests/state_test.go

@@ -174,6 +174,7 @@ func runBenchmarkFile(b *testing.B, path string) {
 		return
 	}
 	for _, t := range m {
+		t := t
 		runBenchmark(b, &t)
 	}
 }