ci: Put CODEOWNERS in the correct folder (#11861)

Per the docs:
https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners#codeowners-file-location

> file called CODEOWNERS in the .github/, root, or docs/ directory of
the repository, in the branch where you'd like to add the code owners.

But also, in our case:
> If CODEOWNERS files exist in more than one of those locations, GitHub
will search for them in that order and use the first one it finds.

So we just need the one file.

Author: ryan953

.github/CODEOWNERS

@@ -1 +1,5 @@
-
+packages/replay-internal                                   @getsentry/replay-sdk-web
+packages/replay-worker                            @getsentry/replay-sdk-web
+packages/replay-canvas                            @getsentry/replay-sdk-web
+packages/feedback                                 @getsentry/feedback-sdk
+dev-packages/browser-integration-tests/suites/replay  @getsentry/replay-sdk-web