chore: extending CODEOWNERS (#3051)

In this PR, I've updated the CODEOWNERS file to include my GitHub handle
in the relevant sections. I seek confirmation from reviewers to ensure
my additions align with our current ownership policies. If there are
sections where my ownership is not applicable, kindly inform me so I can
revise my PR accordingly.

.github/CODEOWNERS

@@ -8,11 +8,11 @@
 # directory-level definitions.
 
 # global owners
-* @evan-forbes @rootulp @cmwaters
+* @evan-forbes @rootulp @cmwaters @staheri14
 
 # directory owners
 # NOTE: the directory owners should include the global owners unless the global
 # owner is fully deferring ownership to the directory owner
-docs @liamsi @adlerjohn @evan-forbes @rootulp @cmwaters
-specs @liamsi @adlerjohn @evan-forbes @rootulp @cmwaters
+docs @liamsi @adlerjohn @evan-forbes @rootulp @cmwaters @staheri14
+specs @liamsi @adlerjohn @evan-forbes @rootulp @cmwaters @staheri14
 x/blobstream @rach-id @evan-forbes