Bump cfn-lint from 0.87.6 to 0.87.7 in /.requirements

Bumps [cfn-lint](https://github.com/aws-cloudformation/cfn-python-lint) from 0.87.6 to 0.87.7.
- [Release notes](https://github.com/aws-cloudformation/cfn-python-lint/releases)
- [Changelog](https://github.com/aws-cloudformation/cfn-lint/blob/v0.87.7/CHANGELOG.md)
- [Commits](aws-cloudformation/cfn-lint@v0.87.6...v0.87.7)

---
updated-dependencies:
- dependency-name: cfn-lint
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

.requirements/cfn-lint.txt

@@ -1 +1 @@
-cfn-lint==0.87.6
+cfn-lint==0.87.7