devel/php*-intl: unbreak build with ICU 70

In file included from breakiterator/breakiterator_class.cpp:21:
breakiterator/codepointiterator_internal.h:40:17: error: virtual function 'operator==' has a different return type ('UBool' (aka 'signed char')) than the function it overrides (which has return type 'bool')

virtual UBool operator==(const BreakIterator& that) const;
        ~~~~~ ^

/usr/local/include/unicode/brkiter.h:127:18: note: overridden virtual function is here

virtual bool operator==(const BreakIterator&) const = 0;
        ~~~~ ^

PR: 258794
Reported by: antoine (via exp-run)