Raise the required python version to 3.13 and remove Pipfile.lock

Author: hrnciar

.github/workflows/update-calendar.yml

@@ -19,7 +19,7 @@ jobs:
         repository: fedora-python/python-release-schedule-ical
     - uses: actions/setup-python@v5
       with:
-        python-version: '3.8'
+        python-version: '3.13'
     - uses: dschep/install-pipenv-action@v1
     - name: Install dependencies
       run: pipenv install

Pipfile

@@ -16,4 +16,4 @@ python-dateutil = ">=2.8"
 lxml = "*"
 
 [requires]
-python_version = "3.8"
+python_version = "3.13"