add @cristaloleg to .github/CODEOWNERS (#3418)

<!--
Thank you for submitting a pull request!

Please make sure you have reviewed our contributors guide before
submitting your
first PR.

Please ensure you've addressed or included references to any related
issues.

Tips:
- Use keywords like "closes" or "fixes" followed by an issue number to
automatically close related issues when the PR is merged (e.g., "closes
#123" or "fixes #123").
- Describe the changes made in the PR.
- Ensure the PR has one of the required tags (kind:fix, kind:misc,
kind:break!, kind:refactor, kind:feat, kind:deps, kind:docs, kind:ci,
kind:chore, kind:testing)

-->

- Expand individual members of CODEOWNERS
- (we should consider there being a @node GitHub team for this
eventually)

.github/CODEOWNERS

@@ -7,6 +7,6 @@
 # global owners are only requested if there isn't a more specific
 # codeowner specified below. For this reason, the global codeowners
 # are often repeated in package-level definitions.
-* @renaynay @Wondertan @vgonkivs @distractedm1nd @walldiss @ramin
+* @renaynay @Wondertan @vgonkivs @distractedm1nd @walldiss @ramin @cristaloleg
 
 docs/adr @adlerjohn @liamsi