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)

1 files changed, 2 insertions, 2 deletions

diff --git a/modules/templates/helper_test.go b/modules/templates/helper_test.go
index e2997cb853..5ebae7afef 100644
--- a/modules/templates/helper_test.go
+++ b/modules/templates/helper_test.go
@@ -17,8 +17,8 @@ func TestSubjectBodySeparator(t *testing.T) {
 			assert.Empty(t, subject, "no subject found, but one expected")
 			assert.Equal(t, body, input)
 		} else {
-			assert.Equal(t, subject, string(input[0:loc[0]]))
-			assert.Equal(t, body, string(input[loc[1]:]))
+			assert.Equal(t, subject, input[0:loc[0]])
+			assert.Equal(t, body, input[loc[1]:])
 		}
 	}