Add purpur as a supported loader tag on modrinth

.github/workflows/generic.platform_uploads.yml

@@ -109,7 +109,7 @@ jobs:
         changelog: ${{ steps.release-artifact.outputs.body }}
         game_versions: 1.21.10, 1.21.9, 1.21.8, 1.21.7, 1.21.6, 1.21.5, 1.21.4, 1.21.3, 1.21.2, 1.21.1, 1.21, 1.20.6, 1.20.5, 1.20.4, 1.20.3, 1.20.2, 1.20.1, 1.20, 1.19.4, 1.19.3, 1.19.2, 1.19.1, 1.19, 1.18.2
         version_type: ${{ steps.parse-release-type.outputs.release_type }}
-        loaders: bukkit, spigot, paper
+        loaders: bukkit, spigot, paper, purpur
         dependencies: ${{ inputs.modrinth_dependencies }}
 
     - name: Upload to DBO