feat: install python in ci container

.forgejo/workflows/build.yml

@@ -8,6 +8,8 @@ jobs:
     steps:
       - uses: https://code.forgejo.org/actions/checkout@v3
       - run: |
-          pip install -r requirements.txt
+          apt update
+          apt install --yes python3-pip
+          pip3 install -r requirements.txt
           ./build.py
 

.forgejo/workflows/upload.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: https://code.forgejo.org/actions/checkout@v3
       - run: |
           apt-get update
-          apt-get install --yes --no-install-recommends rsync openssh-client
+          apt-get install --yes --no-install-recommends rsync openssh-client python3-pip
           pip3 install -r requirements.txt
           ./build.py
           mkdir -p .ssh && chmod 0700 .ssh