update CODEOWNERS for various synthetics spec files #17430

Job	Run time
pre-commit / pre-commit	23s
test / test (jruby-9.4.12.0, ubuntu-latest)	3m 47s
test / test (3.2, ubuntu-latest)	2m 25s
examples / examples	2m 34s
test / test (2.7, ubuntu-latest)	3m 0s
report	6s
	12m 15s

Provide feedback