Update unit_source.yml for ansible-core 2.20

Added support for ansible-core 2.20 and ansible-compat installation.

Author: KB-perByte

.github/workflows/unit_source.yml

@@ -62,10 +62,11 @@ jobs:
       matrix:
         ansible-version:
           # ansible-core 2.15 reached EOL on November 2024
-          - stable-2.16
+          # - stable-2.16
           - stable-2.17
           - stable-2.18
           - stable-2.19
+          - stable-2.20
           - milestone
           - devel
         python-version:
@@ -106,6 +107,9 @@ jobs:
         run: sudo apt update && sudo apt install libssh-dev
         if: ${{ matrix.python-version >= 3.12 }}
       # extra install step ends
+      - name: Install ansible-compat, for tests
+        shell: bash
+        run: python -m pip install ansible-compat
 
       - name: Install ansible-core (${{ matrix.ansible-version }})
         run: python3 -m pip install https://github.com/ansible/ansible/archive/${{ matrix.ansible-version }}.tar.gz --disable-pip-version-check