Installs Python 3.9 on linux

Author: blarfoon

.github/workflows/all_os.yml

@@ -138,6 +138,8 @@ jobs:
           rustup component add clippy rustfmt
           rustc --version
           cargo --version
+      - name: Install Python 3.9
+        run: yum install -y python39
       - name: Prepare
         run: |
           source "$HOME/.cargo/env"