Enable gocritic equalFold and fix issues (#34952)

Continuation of https://github.com/go-gitea/gitea/pull/34678.

---------

Signed-off-by: silverwind <me@silverwind.io>

modules/setting/actions.go

@@ -62,11 +62,11 @@ func (c logCompression) IsValid() bool {
 }
 
 func (c logCompression) IsNone() bool {
-	return strings.ToLower(string(c)) == "none"
+	return string(c) == "none"
 }
 
 func (c logCompression) IsZstd() bool {
-	return c == "" || strings.ToLower(string(c)) == "zstd"
+	return c == "" || string(c) == "zstd"
 }
 
 func loadActionsFrom(rootCfg ConfigProvider) error {