Make target install-local does not work

[nezdolik]

Getting bunch of compilation errors when invoking make install-local. It did not work before as well, see #1805

[jrajahalme]

clang.bazelrc may be stale. Remove and re-create with make clang.bazelrc & check that clang is of the required version.

[nezdolik]

Fixed in envoyproxy/envoy#45657. This turned out not to be relevant to cilium-proxy itself but to external dependency code (cel) in envoy. Worth to note that issue seems to only manifest for linux builds.