Fix typo in release-notes directory link in GitHub workflow (#20581)

# Objective

For example, in:

- #19864 (comment)

The link to the directory containing the release notes is broken.

## Solution

Fix the link.

## Testing

Copy pasted the new link in URL bar.

Author: ariofrio

.github/workflows/action-on-PR-labeled.yml

@@ -70,5 +70,5 @@ jobs:
               repo: context.repo.repo,
               body: `It looks like your PR has been selected for a highlight in the next release blog post, but **you didn't provide a release note**.
 
-              Please review the [instructions for writing release notes](https://github.com/bevyengine/bevy/tree/main/release-content/release_notes.md), then expand or revise the content in the [release notes directory](https://github.com/bevyengine/bevy/tree/main/release-content/release_notes) to showcase your changes.`
+              Please review the [instructions for writing release notes](https://github.com/bevyengine/bevy/tree/main/release-content/release_notes.md), then expand or revise the content in the [release notes directory](https://github.com/bevyengine/bevy/tree/main/release-content/release-notes) to showcase your changes.`
             })