CI: run nightly tests only on main (#569)

* CI: run nightly tests only on main

* avoid running optional tests on forks

* test

* skip normal tests on non-main branches

Author: twoertwein

.github/workflows/optional.yml

@@ -0,0 +1,40 @@
+name: 'Optional'
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  nightly:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Install project dependencies
+      uses: ./.github/setup
+      with:
+        os: ubuntu-latest
+        python-version: '3.10'
+
+    - name: Run pytest (against pandas nightly)
+      run: poetry run poe pytest --nightly
+
+  mypy_nightly:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Install project dependencies
+      uses: ./.github/setup
+      with:
+        os: ubuntu-latest
+        python-version: '3.10'
+
+    - name: Run mypy tests with mypy nightly
+      run: poetry run poe mypy --mypy_nightly

.github/workflows/test.yml

@@ -1,7 +1,11 @@
 name: 'Test'
 
 on:
-  [push, pull_request, workflow_dispatch]
+  push:
+    branches:
+      - main
+  pull_request:
+  workflow_dispatch:
 
 env:
   MPLBACKEND: 'Agg'
@@ -25,11 +29,6 @@ jobs:
         os: ${{ matrix.os }}
         python-version: ${{ matrix.python-version }}
 
-    - name: Show poetry python location (Windows)
-      shell: pwsh
-      run: poetry run where python
-      if: matrix.os == 'windows-latest'
-
     - name: Run mypy on 'tests' (using the local stubs) and on the local stubs
       run: poetry run poe mypy
 
@@ -42,22 +41,6 @@ jobs:
     - name: Install pandas-stubs and run tests on the installed stubs
       run: poetry run poe test_dist
 
-  nightly:
-    runs-on: ubuntu-latest
-    timeout-minutes: 10
-
-    steps:
-    - uses: actions/checkout@v3
-
-    - name: Install project dependencies
-      uses: ./.github/setup
-      with:
-        os: ubuntu-latest
-        python-version: '3.10'
-
-    - name: Run pytest (against pandas nightly)
-      run: poetry run poe pytest --nightly
-
   precommit:
     runs-on: ubuntu-latest
     timeout-minutes: 10
@@ -66,19 +49,3 @@ jobs:
     - uses: actions/checkout@v3
 
     - uses: pre-commit/action@v3.0.0
-
-  mypy_nightly:
-    runs-on: ubuntu-latest
-    timeout-minutes: 10
-
-    steps:
-    - uses: actions/checkout@v3
-
-    - name: Install project dependencies
-      uses: ./.github/setup
-      with:
-        os: ubuntu-latest
-        python-version: '3.10'
-
-    - name: Run mypy tests with mypy nightly
-      run: poetry run poe mypy --mypy_nightly