script: remove call to set ccache option run_second_cpp

script: remove call to set ccache option run_second_cpp

Remove the call to ccache to set run_second_cpp=true because ccache
no longer supports this option. See
https://ccache.dev/releasenotes.html#_ccache_4_12
for more information.

My reading of the ccache release notes & documentation is that when this
option was available the default was true. This is what we were setting
so removing it should not change behavior for ccache, at least most
recent versions. Commit 4cb5a590537a9caaf61db42ce8ea123d2ab961f3 seems
to be the source of this line that sets run_second_cpp=true but that
change does not clearly say why it is being explicitly set, so I think
it's safe to remove.

Signed-off-by: John Mulligan <jmulligan@redhat.com>