support using system certificates via 'truststore' (#6582)

https://github.com/mikf/gallery-dl/issues/6582#issuecomment-2989290495

.github/workflows/executables.yml

@@ -72,6 +72,7 @@ jobs:
     - name: Build executable
       run: |
         pip install requests requests[socks] yt-dlp[default] pyyaml ${{ matrix.python-packages }} pyinstaller
+        pip install truststore || true
         python ./scripts/pyinstaller.py --label '${{ env.LABEL }}'
 
     - uses: actions/upload-artifact@v4