Context

The check-fmt tool checks that example test files have lines wrapped at 80 characters to keep them readable when rendered on pkg.go.dev. Currently, as part of the migration of check_fmt.sh to a Go program (GODRIVER-3936), the check only covers files matching the plural form *_examples_test.go. It should also cover the singular form *_example_test.go, as both are used in the repo for example tests.

Expanding the check to cover *_example_test.go exposes existing line length violations in bson/decoder_example_test.go:

• Line 68: 99 characters
• Line 113: 99 characters
• Line 123: 81 characters
• Line 182: 98 characters

Definition of done

• The check-fmt tool is updated to check both *_examples_test.go and *_example_test.go files.
• All lines in bson/decoder_example_test.go are wrapped at 80 characters or fewer, excluding lines containing URI-like strings in comments (e.g. // https://...) or testable example output markers (e.g. // Output: ...), which are intentionally exempt from the line length limit.
• The task check-fmt command passes locally with no violations.