test: mark test-inspector-network-fetch as flaky on Windows

test: mark test-inspector-network-fetch as flaky on Windows · nodejs/node@a9511a6

Original file line number	Diff line number	Diff line change
`@@ -26,6 +26,8 @@ test-async-context-frame: PASS, FLAKY`
`26`	`26`	`test-runner-run-watch: PASS, FLAKY`
`27`	`27`	`# https://github.com/nodejs/node/issues/56794`
`28`	`28`	`test-fs-cp: PASS, FLAKY`
	`29`	`+# https://github.com/nodejs/node/issues/59090`
	`30`	`+test-inspector-network-fetch: PASS, FLAKY`
`29`	`31`
`30`	`32`	`# https://github.com/nodejs/node/issues/56751`
`31`	`33`	`test-without-async-context-frame: PASS, FLAKY`