Avoid running nightly on forks

Author: BeyondEvil

.github/workflows/nightly.yml

@@ -6,4 +6,5 @@ on:
 
 jobs:
   tests:
+    if: github.repository_owner == 'pytest-dev'
     uses: ./.github/workflows/test.yml

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
- requires = ["poetry-core>=1.0.0"]
- build-backend = "poetry.core.masonry.api"
+requires = ["poetry-core>=1.0.0"]
+build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "pytest-variables"