Xcode: Explicitly disable deprecated user include path feature
The ALWAYS_SEARCH_USER_PATHS
feature is documented to search the
paths in USER_HEADER_SEARCH_PATHS
before HEADER_SEARCH_PATHS
. The
behavior has been long discouraged and was deprecated by Xcode 8.3.
Furthermore, Xcode explicitly disables this setting when creating new
projects. We can do that too since we do not generate any user header
search paths anyway.
Previously we always set USE_HEADERMAP
to NO
to prevent Xcode's
warning about an ancient "header map" feature deprecation. However,
this somehow breaks Xcode 14's "Build Documentation" feature. Setting
ALWAYS_SEARCH_USER_PATHS
to NO
seems to prevent the header map
warning too, so drop USE_HEADERMAP
to fix the documentation feature.
Fixes: #24379