Use older of GraphicsMagic/ImageMagick in some PHP 7 versions

Author: mlocati

.github/workflows/create-images.yml

@@ -208,9 +208,9 @@ jobs:
             imagemagick-version: "7.1.0-8"
           - php-version: "7.2"
             graphicsmagic-version: "1.3.36"
-            imagemagick-version: "7.1.0-8"
+            imagemagick-version: "6.8.9-10"
           - php-version: "7.3"
-            graphicsmagic-version: "1.3.36"
+            graphicsmagic-version: "1.3.23"
             imagemagick-version: "7.1.0-8"
           - php-version: "7.4"
             graphicsmagic-version: "1.3.36"