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

modules/git/repo_commit.go

@@ -251,18 +251,18 @@ func (repo *Repository) CommitsByFileAndRange(opts CommitsByFileAndRangeOptions)
 		return nil, err
 	}
 
-	len := objectFormat.FullLength()
+	length := objectFormat.FullLength()
 	commits := []*Commit{}
-	shaline := make([]byte, len+1)
+	shaline := make([]byte, length+1)
 	for {
 		n, err := io.ReadFull(stdoutReader, shaline)
-		if err != nil || n < len {
+		if err != nil || n < length {
 			if err == io.EOF {
 				err = nil
 			}
 			return commits, err
 		}
-		objectID, err := NewIDFromString(string(shaline[0:len]))
+		objectID, err := NewIDFromString(string(shaline[0:length]))
 		if err != nil {
 			return nil, err
 		}