[6.14.z] Add Python 3.13 for PR checks in GHA (#1269)

(cherry picked from commit 8753c80)

Author: Gauravtalreja1

.github/workflows/merge_to_master.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.10', '3.11', '3.12']
+        python-version: ['3.10', '3.11', '3.12', '3.13']
     steps:
       - name: Checkout Nailgun
         uses: actions/checkout@v4
@@ -61,10 +61,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@master
-      - name: Setup python 3.10
+      - name: Setup python
         uses: actions/setup-python@v5
         with:
-          python-version: '3.10'
+          python-version: '3.13'
       - name: Install pypa/build
         run: python -m pip install build --user
       - name: Build a binary wheel and a source tarball

.github/workflows/pull_requests.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.10', '3.11', '3.12']
+        python-version: ['3.10', '3.11', '3.12', '3.13']
     steps:
       - name: Checkout Nailgun
         uses: actions/checkout@v2