✅ Fix some action labels (#26490)

Co-authored-by: thisiskeithb <13375512+thisiskeithb@users.noreply.github.com>
Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,7 +1,7 @@
 name: 🪲 Report a bug
 description: Create a bug report to help improve Marlin Firmware
 title: "[BUG] (bug summary)"
-labels: 'Bug: Potential ?'
+labels: ["Bug: Potential ?"]
 body:
   - type: markdown
     attributes:

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,7 +1,7 @@
 name: ✨ Request a feature
 description: Request a new Marlin Firmware feature
 title: "[FR] (feature summary)"
-labels: 'T: Feature Request'
+labels: ["T: Feature Request"]
 body:
   - type: markdown
     attributes: