gitlab-ci: Allow non-devs to run package pipelines from MR description

Following 6245e4ee

In addition to producing testable packages by adding certain labels
(which only developers can do), now we can produce such packages by
adding the same label in the issue description. This facilitates to
non-developers generating such packages (e.g. new GsoC contributors).

.gitlab-ci.yml

@@ -322,7 +322,7 @@ gimp-debian-nonreloc:
 .debian:
   extends: .debian-nonreloc
   rules:
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:AppImage.*/'
+    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:AppImage.*/ || $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:AppImage.*/'
       interruptible: true
     - if: '$GIMP_CI_APPIMAGE != null || "$[[ inputs.distribution_pipeline ]]" =~ /.*GIMP_CI_APPIMAGE.*/'
     - <<: *CI_RELEASE
@@ -390,7 +390,7 @@ gimp-debian:
   #We need to specify this since .flatpak from flatpak_ci_initiative.yml sets to true
   interruptible: false
   rules:
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Flatpak.*/'
+    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Flatpak.*/ || $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Flatpak.*/'
       interruptible: true
     - if: '$GIMP_CI_FLATPAK != null || "$[[ inputs.distribution_pipeline ]]" =~ /.*GIMP_CI_FLATPAK.*/'
   parallel:
@@ -441,7 +441,7 @@ gimp-flatpak:
 .snap:
   extends: .default
   rules:
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Snap.*/'
+    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Snap.*/ || $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Snap.*/'
       interruptible: true
     - if: '$GIMP_CI_SNAP != null || "$[[ inputs.distribution_pipeline ]]" =~ /.*GIMP_CI_SNAP.*/'
     - <<: *CI_RELEASE
@@ -520,16 +520,16 @@ gimp-snap:
     #Non developers (e.g. on MRs), however, can create x64-only installers (.exe or .msix)
     - if: '$RUNNER == "windows-aarch64" && $CI_PROJECT_NAMESPACE != "GNOME"'
       when: never
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Windows Installer.*/ && $CI_MERGE_REQUEST_LABELS =~ /.*Package:Microsoft Store.*/'
+    - if: '($CI_MERGE_REQUEST_LABELS =~ /.*Package:Windows Installer.*/ && $CI_MERGE_REQUEST_LABELS =~ /.*Package:Microsoft Store.*/) || ($CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Windows Installer.*/ && $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Microsoft Store.*/)'
       interruptible: true
       variables:
         INSTALLER_OPTION: '-Dwindows-installer=true'
         STORE_OPTION: '-Dms-store=true'
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Windows Installer.*/ && $CI_JOB_NAME !~ /.*store.*/'
+    - if: '($CI_MERGE_REQUEST_LABELS =~ /.*Package:Windows Installer.*/ || $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Windows Installer.*/) && $CI_JOB_NAME !~ /.*store.*/'
       interruptible: true
       variables:
         INSTALLER_OPTION: '-Dwindows-installer=true'
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Microsoft Store.*/ && $CI_JOB_NAME !~ /.*eol.*/ && $CI_JOB_NAME !~ /.*installer.*/'
+    - if: '($CI_MERGE_REQUEST_LABELS =~ /.*Package:Microsoft Store.*/ || $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Microsoft Store.*/) && $CI_JOB_NAME !~ /.*eol.*/ && $CI_JOB_NAME !~ /.*installer.*/'
       interruptible: true
       variables:
         STORE_OPTION: '-Dms-store=true'
@@ -652,7 +652,7 @@ gimp-win-eol:
 .macos-inhouse:
   extends: .default
   rules:
-    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Macos Dmg.*/'
+    - if: '$CI_MERGE_REQUEST_LABELS =~ /.*Package:Macos Dmg.*/ || $CI_MERGE_REQUEST_DESCRIPTION =~ /.*Package:Macos Dmg.*/'
       interruptible: true
       variables:
         OPT_PREFIX: /opt/macports

.gitlab/merge_request_templates/default.md

@@ -9,7 +9,7 @@
   "*Allow commits from members who can merge to the target branch.*"
 
 - No AI-generated contents allowed (neither code nor text, images…).
-  Only human created works please! 
-  
-- You can request the devs to allow installable packages to be
-  generated from this MR by writing ~Package: in the comments -->
+  Only human created works please!
+
+- If needed, you can create installable packages to be generated from
+  each push to this MR by writing ~Package: in this MR description -->