PYTHON-5131 [v4.11] Migrate off of Ubuntu 20.04 GitHub Actions Runners (#2182)

Author: blink1073

.github/workflows/dist.yml

@@ -34,11 +34,11 @@ jobs:
         # Github Actions doesn't support pairing matrix values together, let's improvise
         # https://github.com/github/feedback/discussions/7835#discussioncomment-1769026
         buildplat:
-        - [ubuntu-20.04, "manylinux_x86_64", "cp3*-manylinux_x86_64"]
-        - [ubuntu-20.04, "manylinux_aarch64", "cp3*-manylinux_aarch64"]
-        - [ubuntu-20.04, "manylinux_ppc64le", "cp3*-manylinux_ppc64le"]
-        - [ubuntu-20.04, "manylinux_s390x", "cp3*-manylinux_s390x"]
-        - [ubuntu-20.04, "manylinux_i686", "cp3*-manylinux_i686"]
+        - [ubuntu-latest, "manylinux_x86_64", "cp3*-manylinux_x86_64"]
+        - [ubuntu-latest, "manylinux_aarch64", "cp3*-manylinux_aarch64"]
+        - [ubuntu-latest, "manylinux_ppc64le", "cp3*-manylinux_ppc64le"]
+        - [ubuntu-latest, "manylinux_s390x", "cp3*-manylinux_s390x"]
+        - [ubuntu-latest, "manylinux_i686", "cp3*-manylinux_i686"]
         - [windows-2019, "win_amd6", "cp3*-win_amd64"]
         - [windows-2019, "win32", "cp3*-win32"]
         - [macos-14, "macos", "cp*-macosx_*"]

.github/workflows/test-python.yml

@@ -54,7 +54,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-20.04]
+        os: [ubuntu-latest]
         python-version: ["3.9", "pypy-3.10", "3.13", "3.13t"]
     name: CPython ${{ matrix.python-version }}-${{ matrix.os }}
     steps: