make check check-local quits when assertion fails

[BrianInglis]

I would expect each test result to be reported OK/FAIL/XFAIL/PASS and testing to continue.

Cygwin x86_64 64 bit CI build check:

...
2022-02-19T17:11:14.9942012Z   /iso_3166/3.x/find all codes:                                        OK
2022-02-19T17:11:14.9966613Z   /iso_3166/3.x/find all codes in locale 'fr':                         **
2022-02-19T17:11:14.9967813Z ERROR:$HOME/libisocodes/libisocodes-1.2.4-1.x86_64/build/test_iso_3166.vala.c:980:__lambda13_: assertion failed: (e[0].name == "Allemagne")
2022-02-19T17:11:15.1028571Z FAIL
2022-02-19T17:11:15.1031898Z GTester: last random seed: R02S722263d2c2eb94e137c33dcc2deaa4d0
2022-02-19T17:11:15.1047463Z make[2]: *** [Makefile:1690: check-local] Terminated
...

Cygwin x86_64 64 bit Desktop build check:

...
  /iso_3166_2/3.x/find all codes in locale 'fr':                       OK
  /iso_3166_2/3.x/call find_code() without argument:                   **
ERROR:$HOME/src/cygwin/libisocodes/libisocodes-1.2.4-1.x86_64/build/test_iso_3166_2.vala.c:587:__lambda29_: assertion failed: (error is ISOCodesError.CODE_NOT_DEFINED)
FAIL
GTester: last random seed: R02S966c22862db6004a5748654eeff9b962
make[2]: *** [Makefile:1690: check-local] Terminated
...

Cygwin i686 32 bit build check:

...
  /iso_15924/3.x/find all codes:                                       OK
  /iso_15924/3.x/find all codes in locale 'fr':                        **
ERROR:$HOME/src/cygwin/libisocodes/libisocodes-1.2.4-1.i686/build/test_iso_15924.vala.c:451:__lambda94_: assertion failed: (e[0].name == "bengali")
FAIL
GTester: last random seed: R02S7e9b16e5cfdb77571fb4b4f5b65c8240
make[2]: *** [Makefile:1690: check-local] Terminated
...

Cygwin uses newlib under Windows not glibc so some languages (e.g. Esperanto), territories (e.g. embargoed/sanctioned), or combos, or UTF-8 ops (e.g. regexp classes) may not be supported or return the same results.
The same applies to musl, FreeBSD, MacOSX, and other libc alternatives; e.g. see $ info sed 'sed reg' locale bottom of node, section labelled 5.9.3 Multibyte regexp character classes.