Change nightly release title from "Nightly Release" to "Nightly mdev Build"

Updated the release name in nightly.yml to better reflect that this is a
development build (mdev) rather than a production release.

Co-authored-by: softhack007 <91616163+softhack007@users.noreply.github.com>

.github/workflows/nightly.yml

@@ -37,7 +37,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           tag_name: nightly
-          name: 'Nightly Release $$'
+          name: 'Nightly mdev Build $$'
           prerelease: true
           body: ${{ steps.changelog.outputs.changelog }}
           files: |