ci: bump action version for node16 update and other GitHub action war…

…nings

GitHub actions warns:
Node.js 12 actions are deprecated. For more information see:
https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/.
Please update the following actions to use Node.js 16:
FedericoCarboni/setup-ffmpeg, codecov/codecov-action

codecov-action:
 - is fixed by bumping to v3 (uses node16 instead of node12)
setup-ffmpeg:
 - has a patch for node12->node16 but the release is not out yet.
 - now has a lot of warnings about set-output being deprecated:
   submitted issue federicocarboni/setup-ffmpeg#9
setup-python:
 - @v4 removes all the warnings about save-state and set-output that @V3 had

.github/workflows/tests.yml

@@ -14,7 +14,7 @@ jobs:
         id: setup-ffmpeg
 
       - name: Set up Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.7"
           cache: "pip"
@@ -41,7 +41,7 @@ jobs:
           # Legal check: make sure we don't have or introduce GPL dependencies
           if pip-licenses | grep -v 'Artistic License' | grep -v LGPL | grep GNU; then echo 'Please avoid introducing *GPL dependencies'; false; fi
 
-      - uses: codecov/codecov-action@v2
+      - uses: codecov/codecov-action@v3
         with:
           directory: ./test
           fail_ci_if_error: true # optional (default = false)
@@ -56,7 +56,7 @@ jobs:
         id: setup-ffmpeg
 
       - name: Set up Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.7"
           cache: "pip"