Add more linters to improve code readability (#19989)

Add nakedret, unconvert, wastedassign, stylecheck and nolintlint linters to improve code readability

- nakedret - https://github.com/alexkohler/nakedret - nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
- unconvert - https://github.com/mdempsky/unconvert - Remove unnecessary type conversions
- wastedassign - https://github.com/sanposhiho/wastedassign -  wastedassign finds wasted assignment statements.
- notlintlint -  Reports ill-formed or insufficient nolint directives
- stylecheck - https://staticcheck.io/docs/checks/#ST - keep style consistent
  - excluded: [ST1003 - Poorly chosen identifier](https://staticcheck.io/docs/checks/#ST1003) and [ST1005 - Incorrectly formatted error string](https://staticcheck.io/docs/checks/#ST1005)

modules/git/repo_branch_nogogit.go

@@ -95,7 +95,7 @@ func callShowRef(ctx context.Context, repoPath, prefix, arg string, skip, limit
 
 		return nil
 	})
-	return
+	return branchNames, countAll, err
 }
 
 func walkShowRef(ctx context.Context, repoPath, arg string, skip, limit int, walkfn func(sha1, refname string) error) (countAll int, err error) {