build-unit-test-docker: update meson to 1.2.3

Yocto is using 1.2.2 but 1.2.3 was just released and has the fixes
for clang and C++23 that we have been carrying.  Enable this in CI.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Idfaa7b0d3894f169ab2b053b843cee707276ffe6
1 file changed