chore: enable forcetypeassert linter, fix issues (#38804)

Enable [`forcetypeassert`](https://github.com/gostaticanalysis/forcetypeassert)
linter to prevent unchecked type assertions. ~650 issues fixed, most
fixes were clean, some use `setting.PanicInDevOrTesting`.

The only behaviour changes are where code would previously send a 500 error
or panic, a 4xx error is now emitted.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/pubsub/redis_test.go

@@ -38,7 +38,8 @@ func TestRedisBroker(t *testing.T) {
 	// RedisBroker tears down its per-topic Redis subscription and internal
 	// state once the last local subscriber cancels.
 	t.Run("CancelCleansTopicState", func(t *testing.T) {
-		b := newBroker(t).(*RedisBroker)
+		b, isRedisBroker := newBroker(t).(*RedisBroker)
+		require.True(t, isRedisBroker)
 		ch, cancel := b.Subscribe(t.Name())
 		cancel()