CI: extend matrix to include Meson 1.2

The tests are run with the latest Meson version, and Meson 1.3 has
been released a while ago. Add Meson 1.2 to the old releases with test
with. Pin the version to 1.2.3 or later, to be able to run on Python
3.12.

Author: dnicolodi

.github/workflows/tests.yml

@@ -75,6 +75,9 @@ jobs:
           - os: ubuntu
             python: '3.11'
             meson: '~=1.1.0'
+          - os: ubuntu
+            python: '3.12'
+            meson: '~=1.2.3'
           # Test with Meson master branch.
           - os: ubuntu
             python: '3.12'