run ppc64le-long-double test again

We intend to run tests in testing-farm and no longer on a github actions
runner. That's why we can include the test again.

tests/snapshot-gating.fmf

@@ -28,12 +28,6 @@ discover:
       url: https://src.fedoraproject.org/tests/clang.git
       ref: main
       filter: "tag:-spoils-installation & tag:-not-in-default"
-      exclude:
-        # The following test only runs with qemu and we're executing in a github
-        # action runner in a container.
-        # See https://src.fedoraproject.org/tests/clang/blob/main/f/ppc64le-long-double/main.fmf#_19
-        # Probably not needed not that we have: https://src.fedoraproject.org/tests/clang/c/bb6d566ab8442d8462d693f339fc227f81b2600e
-        - ppc64le-long-double
     - name: compiler-rt-tests
       how: fmf
       url: https://src.fedoraproject.org/tests/compiler-rt.git