install python if not installed (ubuntu/self-hosted)

.github/actions/xahau-ga-get-commit-message/action.yml

@@ -18,10 +18,11 @@ runs:
   using: 'composite'
   steps:
     - name: Get commit message and set environment variable
-      shell: python
+      shell: bash
       env:
         GH_TOKEN: ${{ github.token }}
       run: |
+        python3 - << 'PY'
         import json
         import os
         import secrets
@@ -72,3 +73,4 @@ runs:
 
         print(f"✓ XAHAU_GA_COMMIT_MSG set (available to all subsequent steps)")
         print("==========================================")
+        PY

.github/workflows/xahau-ga-nix.yml

@@ -182,6 +182,16 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        
+      - name: Install python if not installed
+        run: |
+          if ! which python3 > /dev/null 2>&1; then
+            sudo apt-get update
+            sudo apt-get install -y python3 python-is-python3
+          fi
+          if ! which pip3 > /dev/null 2>&1; then
+            sudo apt-get install -y python3-pip
+          fi
 
       - name: Get commit message
         id: get-commit-message
@@ -194,6 +204,9 @@ jobs:
       - name: Install build dependencies
         run: |
           sudo apt-get update
+          sudo apt install software-properties-common
+          sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
+          sudo apt update
           sudo apt-get install -y ninja-build ${{ matrix.cc }} ${{ matrix.cxx }} ccache
 
           # Install the specific GCC version needed for Clang
@@ -258,7 +271,7 @@ jobs:
           fi
 
           # Install Conan 2
-          pip install --upgrade "conan>=2.0,<3"
+          pip3 install --upgrade "conan>=2.0,<3"
 
       - name: Check environment
         run: |