pgsql: meson: Add support for detecting gss without pkg-config

meson: Add support for detecting gss without pkg-config

This is required as MIT Kerberos does provide neither pkg-config nor cmake
dependency information on windows.

Reported-by: Dave Page <dpage@pgadmin.org>
Reviewed-by: Tristan Partin <tristan@partin.io>
Discussion: https://postgr.es/m/20240709065101.xhc74r3mdg2lmn4w@awork3.anarazel.de
Backpatch: 16-, where meson support was added

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7ed2ce0b257fcceb37bec8520eb293c0522d8681

Modified Files
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meson.build | 50 ++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 44 insertions(+), 6 deletions(-)