Update various dependencies used in actions workflows (#207)

Author: wookie184

.github/workflows/event-validation.yml

@@ -14,12 +14,12 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.8
+          python-version: 3.12
 
       - name: Install dependencies
         run: python -m pip install -r events/requirements.txt
@@ -46,7 +46,7 @@ jobs:
       - name: Upload a Build Artifact
         if: always() && steps.prepare-artifact.outcome == 'success'
         continue-on-error: true
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: pull-request-payload
           path: pull_request_payload.json

events/requirements.txt

@@ -1,3 +1,3 @@
-# Python: 3.8
-python-frontmatter==1.0.0
-pyyaml==5.4.1
+# Python: 3.12
+python-frontmatter==1.1.0
+pyyaml==6.0.1