contrib/rpm: disable eBPF for package builds on Fedora

We have random failures to build on gitlab-ci. Something is wrong,
at least, eBPF is not working reliably. Disable it for now.

contrib/fedora/rpm/NetworkManager.spec

@@ -120,7 +120,12 @@
 %endif
 
 %if 0%{?fedora}
-%global ebpf_enabled yes
+# Altough eBPF would be available on Fedora's kernel, it seems
+# we often get SELinux denials (rh#1651654). But even aside them,
+# bpf(BPF_MAP_CREATE, ...) randomly fails with EPERM. That might
+# be related to `ulimit -l`. Anyway, this is not usable at the
+# moment.
+%global ebpf_enabled no
 %else
 %global ebpf_enabled no
 %endif