Relax pyyaml version

Author: timsavage

.github/workflows/tests.yml

@@ -1,4 +1,4 @@
-name: Run Tests
+  name: Run Tests
 
 on:
   push:
@@ -30,7 +30,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip poetry
-        python -m pip wheel --use-pep517 "pyyaml (==6.0)"
+        python -m pip wheel --use-pep517 "pyyaml (~=6.0)"
         poetry install --all-extras --no-root
 
     - name: Test with pytest