php8: module selection affects other sub-packages

php8: module selection affects other sub-packages

Fixes: php8: global package dependency changes based on module
selection

Fixes: #28078
As described in #28078 and #28075,

Some binaries gain a dependency on libstdcpp when mod-gettext is included
in the build, however this was not explicitly declared, so packaging
fails with (e.g.):

Package php8-cgi is missing dependencies for the following libraries:
libstdc++.so.6

In contrast to #28075, this commit takes the approach:

* Make use of --with-gettext depend on a configure flag (enabled by
  default, since that matches current full build behaviour)
* Make sub-packages which require --with-gettext depend on the
  configure flag

This means that e.g. php-cgi would not have gettext support if the
configure flag was disabled, and e.g. php-mod-gettext and php-mod-intl
would not be selectable.

Signed-off-by: Daniel F. Dickinson <[email protected]>