Update .github/workflows/typespec-python-regen.yml

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: iscai-msft

.github/workflows/typespec-python-regen.yml

@@ -27,6 +27,8 @@ jobs:
     steps:
       - name: Checkout azure-sdk-for-python
         uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
 
       - name: Determine typespec ref
         id: ref