chore(lint): add new linters and update codebase

- add canonicalheader
- add copyloopvar
- add fatcontext
- add intrange

internal/updater/resolver/ips_test.go

@@ -31,7 +31,6 @@ func Test_uniqueIPsToSlice(t *testing.T) {
 		},
 	}
 	for name, testCase := range testCases {
-		testCase := testCase
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 			outputIPs := uniqueIPsToSlice(testCase.inputIPs)