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.

core/rawdb/freezer_test.go

@@ -277,7 +277,7 @@ func TestFreezerReadonlyValidate(t *testing.T) {
 
 	// Re-openening as readonly should fail when validating
 	// table lengths.
-	f, err = NewFreezer(dir, "", true, 2049, tables)
+	_, err = NewFreezer(dir, "", true, 2049, tables)
 	if err == nil {
 		t.Fatal("readonly freezer should fail with differing table lengths")
 	}

core/rawdb/freezer_utils_test.go

@@ -43,7 +43,7 @@ func TestCopyFrom(t *testing.T) {
 		{"foo", "bar", 8, true},
 	}
 	for _, c := range cases {
-		os.WriteFile(c.src, content, 0644)
+		os.WriteFile(c.src, content, 0600)
 
 		if err := copyFrom(c.src, c.dest, c.offset, func(f *os.File) error {
 			if !c.writePrefix {