Fix pre-existing test-expectation and formatting nits in TOML package

Two unrelated pre-existing issues in pkg/yqlib, split out from the
comment-fidelity work:

- The go-toml/v2 2.4.2 bump (#2762) renamed the single-line
  unterminated-string parser error from `basic string not terminated by "`
  to `unterminated basic string`, but the decode-error scenario still
  asserted the old text, so TestTomlScenarios failed. Update it to match.
- gofmt: a comment line in encoder_toml.go was indented with spaces.

pkg/yqlib/toml_test.go

@@ -369,7 +369,7 @@ var tomlScenarios = []formatScenario{
 		skipDoc:       true,
 		description:   "blank",
 		input:         `A = "hello`,
-		expectedError: `bad file 'sample.yml': basic string not terminated by "`,
+		expectedError: `bad file 'sample.yml': unterminated basic string`,
 		scenarioType:  "decode-error",
 	},
 	{