chore: update dependencies and improve post handling logic

- Bump @devvit/protos and @devvit/public-api to version 0.12.22.
- Add @fsvreddit/fsv-devvit-helpers as a dependency.
- Upgrade eslint to version 10.0.0.
- Implement duplicate trigger handling in handlePostCreate and handlePostApprovalAction functions using hasTriggerBeenHandled.
- Update log message in handleAppInstallOrUpgrade to use appSlug instead of appName.

Author: fsvreddit

README.md

@@ -36,6 +36,10 @@ By default, a report will be made:
 
 ## Change History
 
+### v1.2.1
+
+* Mitigate against duplicate actions if the Developer Platform is having issues
+
 ### v1.2
 
 * Added ability to remove posts if a match occurs, with an optional removal message