Update CODEOWNERS

Muthu is working on other tasks and unfortunately doesn't have time to
work on yaml-language-server.
For the time being, I've been handling PR reviews and managing issues.
Updating the CODEOWNERS to reflect this will automatically
request for me to review any new PRs that come in,
and will skip pinging Muthu.

Signed-off-by: David Thompson <davthomp@redhat.com>

Author: datho7561

.github/CODEOWNERS

@@ -1,3 +1,2 @@
 # Global Owners
-* @evidolob
-* @msivasubramaniaan
+* @datho7561