Don't build centos-7-bintar for > 11.4

A new bintar builder (non-EOL) will handle builds
for 11.7/11.8.

For now, it's important that GnuTLS is updated and
can build 11.4

constants.py

@@ -190,7 +190,9 @@
     "ppc64le-debian-sid",
     "x86-debian-sid",
 ]
+
 SUPPORTED_PLATFORMS["11.5"] = SUPPORTED_PLATFORMS["11.4"].copy()
+SUPPORTED_PLATFORMS["11.5"].remove("amd64-centos-7-bintar")
 SUPPORTED_PLATFORMS["11.6"] = SUPPORTED_PLATFORMS["11.5"].copy()
 SUPPORTED_PLATFORMS["11.7"] = SUPPORTED_PLATFORMS["11.6"].copy()
 SUPPORTED_PLATFORMS["11.8"] = SUPPORTED_PLATFORMS["11.7"].copy()