packit: Limit Fedora builds and tests to the 'main' branch

.packit.yaml

@@ -16,10 +16,10 @@ actions:
 
 jobs:
 - job: copr_build
- metadata:
- targets:
+ targets:
  - fedora-all
  trigger: pull_request
+ branch: main
 
 - job: copr_build
  trigger: commit
@@ -32,6 +32,7 @@ jobs:
  trigger: pull_request
  targets:
  - fedora-latest-stable
+ branch: main
 
 - job: propose_downstream
  trigger: release
@@ -52,6 +53,7 @@ jobs:
 - job: tests
  identifier: revdeps
  trigger: pull_request
+ branch: main
  notifications:
  failure_comment:
  message: "Blivet-GUI tests failed for commit {commit_sha}. @vojtechtrefny please check."