github: Only test hardened-refpolicy on distro gentoo

Signed-off-by: Jason Zaman <perfinion@gentoo.org>

Author: perfinion

.github/workflows/build-policy.yml

@@ -30,7 +30,7 @@ jobs:
     strategy:
       matrix:
         # matrix updates must also be duplicated to validate-policy.yml and diff-policy.yml
-        distro: ["redhat", "debian", "gentoo"]
+        distro: ["gentoo"]
         type: ["standard", "mcs", "mls"]
         monolithic: ["y", "n"]
         systemd: ["y", "n"]

.github/workflows/validate-policy.yml

@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        distro: ["redhat", "debian", "gentoo"]
+        distro: ["gentoo"]
         type: ["standard", "mcs", "mls"]
         monolithic: ["y", "n"]
         systemd: ["y", "n"]