Compstate scorer tests depend on PyYAML

Pick a version which is compatible with SRComp, though the later
install of the full dependencies will replace it if needed.

Author: PeterJCLaw

action.yml

@@ -10,15 +10,19 @@ runs:
         # `cache-dependency-path` seems to need to be within the current directory. Use a temporary directory
         #
         tempdir=$(mktemp --directory --tmpdir=. --suffix=-srcomp-validate-action)
-        cp ${{ github.action_path }}/requirements.txt $tempdir/requirements.txt
+        cp ${{ github.action_path }}/**requirements.txt $tempdir
         echo "::set-output name=directory::${tempdir}"
 
     - name: Set up Python
       uses: actions/setup-python@v3
       with:
         python-version: '3.10'
         cache: pip
-        cache-dependency-path: ${{ steps.copy-requirements.outputs.directory }}/requirements.txt
+        cache-dependency-path: ${{ steps.copy-requirements.outputs.directory }}/**requirements.txt
+
+    - name: Install Test Dependencies
+      shell: bash
+      run: pip install -U -r ${{ steps.copy-requirements.outputs.directory }}/test-requirements.txt
 
     - name: Run Scoring tests
       shell: bash

test-requirements.txt

@@ -0,0 +1 @@
+PyYAML>5<6