ci: cleanup (spotDL#1402)

* ci: quote python version numbers

Future proofes for coming 3.10.X versions by chaning 3.10.0 to "3.10"

* ci: remove max parallel

Allow github to maximise number of parallel jobs

Author: Silverarmor

.github/workflows/spotify-downloader-ci.yml

@@ -9,10 +9,9 @@ jobs:
   test:
     runs-on: ${{ matrix.platform }}
     strategy:
-      max-parallel: 4
       matrix:
         platform: [ ubuntu-latest, macos-latest, windows-latest ]
-        python-version: [ 3.6.7, 3.7, 3.8, 3.9, 3.10.0 ]
+        python-version: [ "3.6.7", "3.7", "3.8", "3.9", "3.10" ]
 
     steps:
       - uses: actions/checkout@v2