Remove LGTM badges from the README

Now that LGTM has been deprecated in favor of GitHub code scanning
(CodeQL) we have removed the integration from the organization. As a
result we need to remove these badges.

README.md

@@ -3,8 +3,6 @@
 [![GitHub Build Status](https://github.com/cisagov/skeleton-python-library/workflows/build/badge.svg)](https://github.com/cisagov/skeleton-python-library/actions)
 [![CodeQL](https://github.com/cisagov/skeleton-python-library/workflows/CodeQL/badge.svg)](https://github.com/cisagov/skeleton-python-library/actions/workflows/codeql-analysis.yml)
 [![Coverage Status](https://coveralls.io/repos/github/cisagov/skeleton-python-library/badge.svg?branch=develop)](https://coveralls.io/github/cisagov/skeleton-python-library?branch=develop)
-[![Total alerts](https://img.shields.io/lgtm/alerts/g/cisagov/skeleton-python-library.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/cisagov/skeleton-python-library/alerts/)
-[![Language grade: Python](https://img.shields.io/lgtm/grade/python/g/cisagov/skeleton-python-library.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/cisagov/skeleton-python-library/context:python)
 [![Known Vulnerabilities](https://snyk.io/test/github/cisagov/skeleton-python-library/develop/badge.svg)](https://snyk.io/test/github/cisagov/skeleton-python-library)
 
 This is a generic skeleton project that can be used to quickly get a