[gnome-runtime-images/alatiera/scheduled-stable-rebuilds] avoid rebuilding stable releases unless needed

[Jordan Petridis <jpetridis src gnome org>]

commit e6c44a075314c6ab92d9db49387fa10e291a0ae7
Author: Jordan Petridis <jpetridis gnome org>
Date:   Thu Apr 23 11:50:33 2020 +0300

    avoid rebuilding stable releases unless needed

 .gitlab-ci.yml | 13 +++++++++++++
 1 file changed, 13 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 96599b3..a2bc0f1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -75,6 +75,7 @@ flat-manager-client:
 # Expects ${BRANCH} and ${FD_BRANCH} variables which are the gnome branch and the freedesktop-sdk
 # branch it is based on
 .sdk_template:
+    needs: []
     script:
         # build the flatpak sdk image
         - |
@@ -116,6 +117,10 @@ gnome:3.32:
     variables:
         BRANCH: "3.32"
         FD_BRANCH: "18.08"
+    rules:
+      - if: '$REBUILD_3_32'
+        when: 'always'
+      - when: 'manual'
 
 gnome:3.34:
     stage: runtimes
@@ -123,6 +128,10 @@ gnome:3.34:
     variables:
         BRANCH: "3.34"
         FD_BRANCH: "19.08"
+    rules:
+      - if: '$REBUILD_3_34'
+        when: 'always'
+      - when: 'manual'
 
 gnome:3.36:
     stage: runtimes
@@ -130,3 +139,7 @@ gnome:3.36:
     variables:
         BRANCH: "3.36"
         FD_BRANCH: "19.08"
+    rules:
+      - if: '$REBUILD_3_36'
+        when: 'always'
+      - when: 'manual'