Update CODEOWNERS (#8076)

# Description

Combining two codeowners files into one, with root level pointing to the
file under the `.github` directory. More context in
#8074.

## Type of change

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- This pull request is a minor refactor, code cleanup, test improvement,
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Fixes: #8074

## Contributor checklist
Please verify that the PR meets the following requirements, where
applicable:

- [ ] An overview of proposed schema changes is included in a linked
GitHub issue. -- N/A
- [ ] A design document PR is created in the [design-notes
repository](https://github.com/radius-project/design-notes/), if new
APIs are being introduced. -- N/A
- [ ] If applicable, design document has been reviewed and approved by
Radius maintainers/approvers. -- N/A
- [ ] A PR for the [samples
repository](https://github.com/radius-project/samples) is created, if
existing samples are affected by the changes in this PR. -- N/A
- [ ] A PR for the [documentation
repository](https://github.com/radius-project/docs) is created, if the
changes in this PR affect the documentation or any user facing updates
are made. -- N/A
- [ ] A PR for the [recipes
repository](https://github.com/radius-project/recipes) is created, if
existing recipes are affected by the changes in this PR. -- N/A

Signed-off-by: karishma-chawla <[email protected]>
Co-authored-by: karishma-chawla <[email protected]>

.github/CODEOWNERS

@@ -1,9 +1,2 @@
-# Documentation and examples for what this does:
-#
-#  https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners
-
-# This file is a list of rules, with the last rule being most specific
-# All of the people (and only those people) from the matching rule will be notified
-
-# Default rule: anything that doesn't match a more specific rule goes here
-* @radius-project/maintainers-radius @radius-project/approvers-radius
+# These owners are the maintainers and approvers of this repo
+*       @radius-project/maintainers-radius @radius-project/approvers-radius

CODEOWNERS

@@ -1,2 +1 @@
-# These owners are the maintainers and approvers of this repo
-*       @radius-project/maintainers-radius @radius-project/approvers-radius
+# See the owners for this repo at .github/CODEOWNERS