ci: skip github actions on gitea

.github/workflows/codeql.yml

@@ -10,6 +10,7 @@ on:
 
 jobs:
   analyze:
+    if: ${{ env.GITEA_ACTIONS != 'true' }}
     name: Analyze
     runs-on: ubuntu-latest
     permissions:

.github/workflows/mkdocs.yml

@@ -5,6 +5,7 @@ on:
       - master
 jobs:
   deploy:
+    if: ${{ env.GITEA_ACTIONS != 'true' }}
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

.github/workflows/python-package.yml

@@ -7,6 +7,7 @@ on: [ push ]
 
 jobs:
   build:
+    if: ${{ env.GITEA_ACTIONS != 'true' }}
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2