Remove 1.x versions from upmerges build (#425)

Author: NoResponseMate

.github/workflows/upmerge_pr.yaml

@@ -20,12 +20,6 @@ jobs:
             fail-fast: false
             matrix:
                 include:
-                    -
-                        base_branch: "1.0"
-                        target_branch: "1.1"
-                    -
-                        base_branch: "1.1"
-                        target_branch: "2.0"
                     -
                         base_branch: "2.0"
                         target_branch: "2.1"