Hotfix: Restore stale workflow functionality

The stale workflows are currently failing with the error:

    Invalid workflow file: .github/workflows/stale.yml#L26
    The workflow is not valid. .github/workflows/stale.yml (Line: 26, Col: 11): A sequence was not expected

To fix this, the list of exempt-issues-labels in .github/workflows/stale.yml
must be a  comma separated list. A single quote is placed around the list to
allow for use of colons in label names.

Signed-off-by: Melissa Sulprizio <[email protected]>

.github/workflows/stale.yml

@@ -22,14 +22,7 @@ jobs:
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-issue-label: 'stale'
-        exempt-issue-labels:
-          - 'category: Discussion'
-          - 'category: Feature Request'
-          - 'deferred'
-          - 'help needed: Open Research Problem'
-          - 'help needed: Request Input from Community'
-          - 'never stale'
-          - 'TODO: Documentation'
+        exempt-issue-labels: 'category: Discussion,category: Feature Request,deferred,help needed: Open Research Problem,help needed: Request Input from Community,never stale,TODO: Documentation'
         days-before-issue-stale: 30
         days-before-issue-close: 7
         stale-issue-message: 'This issue has been automatically marked as stale because it has not had recent activity. If there are no updates within 7 days it will be closed. You can add the "never stale" tag to prevent the issue from closing this issue.'

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to GCPy will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased] - TBD
+### Fixed
+- Fixed formatting error in `.github/workflows/stale.yml` that caused the Mark Stale Issues action not to run
+
 ## [1.5.0] - 2024-05-29
 ### Added
 - Script `gcpy/benchmark/modules/benchmark_utils.py`, with common benchmark utility functions