Split into separate jobs

.github/workflows/lint-python.yaml

@@ -1,13 +1,22 @@
 on: [push, pull_request]
 name: Lint Python and Find Syntax Errors
 jobs:
+  mypy:
+    runs-on: ubuntu-latest
+    container:
+      image: archlinux:latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: pacman --noconfirm -Syu python mypy
+      - name: run mypy
+        run: mypy . --ignore-missing-imports
   lint:
     runs-on: ubuntu-latest
     container:
       image: archlinux:latest
     steps:
       - uses: actions/checkout@v2
-      - run: pacman --noconfirm -Syu python python-pip mypy
+      - run: pacman --noconfirm -Syu python python-pip
       - run: python -m pip install --upgrade pip
       - run: pip install flake8 pytest
       - name: Lint with flake8
@@ -16,5 +25,3 @@ jobs:
           flake8 . --count --select=E9,F63,F7 --show-source --statistics
           # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
           flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
-      - name: run mypy
-        run: mypy . --ignore-missing-imports