Enable more revive linter rules (#30608)

Noteable additions:

- `redefines-builtin-id` forbid variable names that shadow go builtins
- `empty-lines` remove unnecessary empty lines that `gofumpt` does not
remove for some reason
- `superfluous-else` eliminate more superfluous `else` branches

Rules are also sorted alphabetically and I cleaned up various parts of
`.golangci.yml`.

(cherry picked from commit 74f0c84fa4245a20ce6fb87dac1faf2aeeded2a2)

Conflicts:
	.golangci.yml
	apply the linter recommendations to Forgejo code as well

models/migrations/v1_20/v250.go

@@ -104,7 +104,7 @@ func ChangeContainerMetadataMultiArch(x *xorm.Engine) error {
 
 		// Convert to new metadata format
 
-		new := &MetadataNew{
+		newMetadata := &MetadataNew{
 			Type:             old.Type,
 			IsTagged:         old.IsTagged,
 			Platform:         old.Platform,
@@ -119,7 +119,7 @@ func ChangeContainerMetadataMultiArch(x *xorm.Engine) error {
 			Manifests:        manifests,
 		}
 
-		metadataJSON, err := json.Marshal(new)
+		metadataJSON, err := json.Marshal(newMetadata)
 		if err != nil {
 			return err
 		}