Drop codecov from CI and readme

.github/workflows/ci.yml

@@ -89,13 +89,6 @@ jobs:
         run: |
           hatch run coverage run setup.py test
           hatch run coverage xml -i
-      - uses: codecov/codecov-action@v4
-        env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
-        with:
-          files: coverage.xml
-          fail_ci_if_error: true
-          verbose: true
       - name: Archive Coverage
         uses: actions/upload-artifact@v4
         with:

README.rst

@@ -4,7 +4,7 @@
 
 A Concrete Syntax Tree (CST) parser and serializer library for Python
 
-|support-ukraine| |readthedocs-badge| |ci-badge| |codecov-badge| |pypi-badge| |pypi-download| |notebook-badge|
+|support-ukraine| |readthedocs-badge| |ci-badge| |pypi-badge| |pypi-download| |notebook-badge|
 
 .. |support-ukraine| image:: https://img.shields.io/badge/Support-Ukraine-FFD500?style=flat&labelColor=005BBB
    :alt: Support Ukraine - Help Provide Humanitarian Aid to Ukraine.
@@ -18,10 +18,6 @@ A Concrete Syntax Tree (CST) parser and serializer library for Python
    :target: https://github.com/Instagram/LibCST/actions/workflows/build.yml?query=branch%3Amain
    :alt: Github Actions
 
-.. |codecov-badge| image:: https://codecov.io/gh/Instagram/LibCST/branch/main/graph/badge.svg
-   :target: https://codecov.io/gh/Instagram/LibCST/branch/main
-   :alt: CodeCov
-
 .. |pypi-badge| image:: https://img.shields.io/pypi/v/libcst.svg
    :target: https://pypi.org/project/libcst
    :alt: PYPI