packit: build Packit with LTO in OpenScanHub

GCC analyzer in some cases depends on information provided by LTO to
generate accurate results, but the LTO support in GCC analyzer is still
experimental, so it's not enabled by default. In Polkit, however, this
seems to work pretty well, so let's tell OSH to build our code with LTO
when running GCC analyzer.

.packit.yaml

@@ -13,6 +13,14 @@ files_to_sync:
 upstream_package_name: polkit
 # downstream (Fedora) RPM package name
 downstream_package_name: polkit
+# arguments for OpenScanHub
+#
+# Note: GCC analyzer in some cases depends on information provided by LTO to
+#       generate accurate results, but the LTO support in GCC analyzer is still
+#       experimental, so it's not enabled by default. In Polkit, however, this
+#       seems to work pretty well, so let's tell OSH to build our code with LTO
+#       when running GCC analyzer.
+csmock_args: --gcc-add-flag=-flto=auto
 
 jobs:
 - job: copr_build