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/auth/httpsign.go

@@ -197,7 +197,11 @@ func VerifyCert(r *http.Request) (*asymkey_model.PublicKey, error) {
 // doVerify iterates across the provided public keys attempting the verify the current request against each key in turn
 func doVerify(verifier httpsig.Verifier, sshPublicKeys []ssh.PublicKey) error {
 	for _, publicKey := range sshPublicKeys {
-		cryptoPubkey := publicKey.(ssh.CryptoPublicKey).CryptoPublicKey()
+		cryptoPublicKey, ok := publicKey.(ssh.CryptoPublicKey)
+		if !ok {
+			continue
+		}
+		cryptoPubkey := cryptoPublicKey.CryptoPublicKey()
 
 		var algos []httpsig.Algorithm