build: Ensure all required checks run on merge_group

And clean up some of the whitespace formatting so that the "name" and
"on" are grouped away from the "jobs".

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
(cherry picked from commit d9f48505fe)

.github/workflows/integration-x86-64.yaml

@@ -1,5 +1,5 @@
 name: Cloud Hypervisor Tests (x86-64)
-on: [pull_request, create]
+on: [pull_request, merge_group]
 
 jobs:
   build:
@@ -9,7 +9,6 @@ jobs:
       matrix:
         runner: ["garm-jammy", "garm-jammy-amd"]
         libc: ["musl", "gnu"]
-    if: github.event_name == 'pull_request'
     name: Tests (x86-64)
     runs-on: ${{ matrix.runner }}
     steps: