Use 3.x designation in python version to test latest version on ubuntu

and mac in CI.

Author: shyuep

.github/workflows/lint.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: '3.x'
 
       - name: Install dependencies
         run: |

.github/workflows/test.yml

@@ -35,11 +35,11 @@ jobs:
             resolution: highest
             extras: ci,optional
           - os: ubuntu-latest
-            python: "3.12"
+            python: '3.x'
             resolution: lowest-direct
             extras: ci,optional
           - os: macos-latest
-            python: "3.10"
+            python: '3.x'
             resolution: lowest-direct
             extras: ci # test with only required dependencies installed