Update stable dependencies on schedule (#6164)

As name says. Currently, every time stable dependencies change (every
time a PR is merged to master), an automatic PR is opened to update the
dependencies. It can be quite annoying to merge a PR and then another
one gets opened immediately afterwards. Thus, this changes the test
workflows to run them on a weekly schedule, and a PR to update stable
dependencies is only opened if the test workflow is triggered by the
schedule.

All changes have been implemented by @timmysilv . I'm just the
messenger.

---------

Co-authored-by: Matthew Silverman <[email protected]>

.github/workflows/interface-unit-tests.yml

@@ -159,7 +159,7 @@ jobs:
       install_pennylane_lightning_master: true
       pytest_coverage_flags: ${{ inputs.pytest_coverage_flags }}
       pytest_markers: torch and not qcut and not finite-diff and not param-shift
-      requirements_file: ${{ strategy.job-index == 0 && 'torch.txt' || '' }}
+      requirements_file: ${{ github.event_name == 'schedule' && strategy.job-index == 0 && 'torch.txt' || '' }}
       disable_new_opmath: ${{ inputs.disable_new_opmath }}
 
 
@@ -227,7 +227,7 @@ jobs:
       pytest_markers: tf and not qcut and not finite-diff and not param-shift
       pytest_additional_args: --splits 3 --group ${{ matrix.group }} --durations-path='.github/workflows/tf_tests_durations.json'
       additional_pip_packages: pytest-split
-      requirements_file: ${{ strategy.job-index == 0 && 'tf.txt' || '' }}
+      requirements_file: ${{ github.event_name == 'schedule' && strategy.job-index == 0 && 'tf.txt' || '' }}
       disable_new_opmath: ${{ inputs.disable_new_opmath }}
 
 
@@ -263,7 +263,7 @@ jobs:
       pytest_markers: jax and not qcut and not finite-diff and not param-shift
       pytest_additional_args: --splits 5 --group ${{ matrix.group }} --durations-path='.github/workflows/jax_tests_durations.json'
       additional_pip_packages: pytest-split
-      requirements_file: ${{ strategy.job-index == 0 && 'jax.txt' || '' }}
+      requirements_file: ${{ github.event_name == 'schedule' && strategy.job-index == 0 && 'jax.txt' || '' }}
       disable_new_opmath: ${{ inputs.disable_new_opmath }}
 
 
@@ -299,7 +299,7 @@ jobs:
       pytest_markers: core and not qcut and not finite-diff and not param-shift
       pytest_additional_args: --splits 5 --group ${{ matrix.group }} --durations-path='.github/workflows/core_tests_durations.json'
       additional_pip_packages: pytest-split
-      requirements_file: ${{ strategy.job-index == 0 && 'core.txt' || '' }}
+      requirements_file: ${{ github.event_name == 'schedule' && strategy.job-index == 0 && 'core.txt' || '' }}
       disable_new_opmath: ${{ inputs.disable_new_opmath }}
 
 
@@ -332,7 +332,7 @@ jobs:
       install_pennylane_lightning_master: true
       pytest_coverage_flags: ${{ inputs.pytest_coverage_flags }}
       pytest_markers: all_interfaces
-      requirements_file: ${{ strategy.job-index == 0 && 'all_interfaces.txt' || '' }}
+      requirements_file: ${{ github.event_name == 'schedule' && strategy.job-index == 0 && 'all_interfaces.txt' || '' }}
       disable_new_opmath: ${{ inputs.disable_new_opmath }}
 
 
@@ -371,7 +371,7 @@ jobs:
       pytest_coverage_flags: ${{ inputs.pytest_coverage_flags }}
       pytest_markers: external
       additional_pip_packages: pyzx pennylane-catalyst matplotlib stim quimb
-      requirements_file: ${{ strategy.job-index == 0 && 'external.txt' || '' }}
+      requirements_file: ${{ github.event_name == 'schedule' && strategy.job-index == 0 && 'external.txt' || '' }}
       disable_new_opmath: ${{ inputs.disable_new_opmath }}
 
 

.github/workflows/tests.yml

@@ -10,6 +10,9 @@ on:
       - synchronize
       - ready_for_review
       - labeled
+  # Scheduled trigger on Monday at 2:47am UTC
+  schedule:
+  - cron: '47 2 * * 1'
 
 concurrency:
   group: unit-tests-${{ github.ref }}