chore(deps): update actions/setup-python action to v2.3.0

Signed-off-by: Renovate Bot <bot@renovateapp.com>

| datasource  | package              | from   | to     |
| ----------- | -------------------- | ------ | ------ |
| github-tags | actions/setup-python | v2.2.2 | v2.3.0 |

.github/workflows/pr-validation.yml

@@ -105,7 +105,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2.2.2
+      - uses: actions/setup-python@v2.3.0
       - uses: actions/setup-go@v2
         with:
           go-version: 1.16