ci: replace SETUPTOOLS_SCM_PRETEND_VERSION -> FOR_PYTEST

This way it can only affect pytest. Don't think it matters here but only
for consistency.

Author: bluetech

.github/workflows/deploy.yml

@@ -16,7 +16,7 @@ jobs:
   package:
     runs-on: ubuntu-latest
     env:
-      SETUPTOOLS_SCM_PRETEND_VERSION: ${{ github.event.inputs.version }}
+      SETUPTOOLS_SCM_PRETEND_VERSION_FOR_PYTEST: ${{ github.event.inputs.version }}
     timeout-minutes: 10
 
     # Required by attest-build-provenance-github.