Be more specific about distro

Instead of vague distro=7 and distro=8 use
7.9 and 8.6 respectedly as our refactored regression
tests now use.
This should fix the "no plans found" issue with 8.6-rhui
upgrade as well as continue running e2e test as part of
8->9 integration tests.

.github/workflows/tmt-tests.yml

@@ -74,6 +74,7 @@ jobs:
       variables: "LEAPP_DEVEL_TARGET_PRODUCT_TYPE=beta;RHSM_SKU=RH00069;TARGET_RELEASE=9.1;TARGET_KERNEL=el9;RHSM_REPOS=rhel-8-for-x86_64-appstream-rpms,rhel-8-for-x86_64-baseos-rpms"
       compose: "RHEL-8.7.0-Nightly"
       pull_request_status_name: "8.7to9.1"
+      tmt_context: "distro=rhel-8.7"
 
   call_workflow_tests_8to9_sst:
     needs: call_workflow_copr_build