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/references/references.go

@@ -379,7 +379,7 @@ func FindRenderizableReferenceAlphanumeric(content string) (bool, *RenderizableR
 	action, location := findActionKeywords([]byte(content), match[2])
 
 	return true, &RenderizableReference{
-		Issue:          string(content[match[2]:match[3]]),
+		Issue:          content[match[2]:match[3]],
 		RefLocation:    &RefSpan{Start: match[2], End: match[3]},
 		Action:         action,
 		ActionLocation: location,
@@ -506,7 +506,7 @@ func getCrossReference(content []byte, start, end int, fromLink, prOnly bool) *r
 	}
 	repo := string(content[start : start+sep])
 	issue := string(content[start+sep+1 : end])
-	index, err := strconv.ParseInt(string(issue), 10, 64)
+	index, err := strconv.ParseInt(issue, 10, 64)
 	if err != nil {
 		return nil
 	}