contrib/googletest: update from 1.14.0 to 1.15.2

[ngie]

Summary

This change updates GoogleTest in base from 1.14.0 to 1.15.2.

The changes between the two versions can be found in this diff of the
two release tags:
https://github.com/google/googletest/compare/v1.14.0...v1.15.2

One notable change is that GoogleTest 1.15.x now officially requires
C++-14 (1.14.x required C++-11).

Merge commit '14f7077fed7d82046bdcbe347004132f08aba886'

Test Plan

$ $ sudo kyua test -k /usr/tests/sys/fs/fusefs/Kyuafile 
access:main  ->  passed  [0.028s]
allow_other:main  ->  passed  [0.035s]
bad_server:main  ->  passed  [0.015s]
bmap:main  ->  passed  [0.024s]
cache:main  ->  passed  [0.063s]
copy_file_range:main  ->  passed  [0.258s]
create:main  ->  passed  [0.038s]
default_permissions:main  ->  passed  [0.008s]
default_permissions_privileged:main  ->  passed  [0.009s]
destroy:main  ->  passed  [0.123s]
dev_fuse_poll:main  ->  passed  [0.136s]
fallocate:main  ->  passed  [0.050s]
fifo:main  ->  passed  [0.012s]
flush:main  ->  passed  [0.022s]
forget:main  ->  passed  [0.126s]
fsync:main  ->  passed  [0.026s]
fsyncdir:main  ->  passed  [0.016s]
getattr:main  ->  passed  [0.136s]
interrupt:main  ->  passed  [0.693s]
io:main  ->  passed  [1.125s]
last_local_modify:main  ->  passed  [0.032s]
link:main  ->  passed  [0.021s]
locks:main  ->  passed  [0.045s]
lookup:main  ->  passed  [0.609s]
lseek:main  ->  passed  [0.044s]
mkdir:main  ->  passed  [0.021s]
mknod:main  ->  passed  [0.023s]
mount:main  ->  passed  [0.024s]
nfs:main  ->  passed  [0.139s]
notify:main  ->  passed  [0.032s]
open:main  ->  passed  [0.040s]
opendir:main  ->  passed  [0.022s]
read:main  ->  passed  [1.003s]
readdir:main  ->  passed  [0.032s]
readlink:main  ->  passed  [0.019s]
release:main  ->  passed  [0.020s]
releasedir:main  ->  passed  [0.017s]
rename:main  ->  passed  [0.027s]
rmdir:main  ->  passed  [0.016s]
setattr:main  ->  passed  [0.045s]
statfs:main  ->  passed  [0.014s]
symlink:main  ->  passed  [0.017s]
unlink:main  ->  passed  [0.023s]
write:main  ->  passed  [0.241s]
xattr:main  ->  passed  [0.069s]

Results file id is usr_tests_sys_fs_fusefs.20241020-014802-248255
Results saved to /root/.kyua/store/results.usr_tests_sys_fs_fusefs.20241020-014802-248255.db

45/45 passed (0 broken, 0 failed, 0 skipped)

[asomers]

Fine by me. Thanks for proactively testing the fusefs test suite build.