chore: Update tidy.yml to use create-pull-request@v6

.github/workflows/tidy.yml

@@ -4,6 +4,8 @@ on:
   push:
     branches:
       - gh-pages
+    paths:
+      - index.html
 
 jobs:
   tidy:
@@ -13,7 +15,7 @@ jobs:
       - uses: actions/checkout@v2
       - run: brew install tidy-html5
       - run: tidy -config tidyconfig.txt -o index.html index.html
-      - uses: peter-evans/create-pull-request@v3
+      - uses: peter-evans/create-pull-request@v6
         with:
           title: "Tidied up document using tidy-html5"
           commit-message: "chore: tidy up index.html"