Revert "Experiment: Add release notes PR link field to pull request template"

This reverts commit 439c8b62c3.

Didn't intend to push this to the main branch, and didn't notice it was
still on there when pushing.

.gitea/pull_request_template.yaml

@@ -20,9 +20,3 @@ body:
     attributes:
       label: "Description"
       hide_label: true
-
-  - type: input
-    attributes:
-      label: "Release Notes Pull Request"
-      description: "Link to a pull request adding this change to the [release notes](https://developer.blender.org/docs/release_notes/). This is highly encouraged for any noteworthy change."
-      placeholder: "URL"