fix: add khrm to reviewers in OWNERS_ALIASES

khrm has been contrubuting pipelines for a while now and https://github.com/tektoncd/pipeline/issues?q=is:pr%20state:closed%20author:khrm and has well over 15 commits to qualify as a reviewer as well. Having him would help strengthen our reviewer team and help with faster reviews.

Author: waveywaves

OWNERS_ALIASES

@@ -21,6 +21,7 @@ aliases:
   - jerop
   - abayer
   - twoGiants
+  - khrm
   # - wlynch (feel free to /cc me into PRs as needed)
 
   apis-approvers:
@@ -45,4 +46,4 @@ aliases:
 # sbwsg
 # dlorenc
 # lbernick
-# bobcatfish
+# bobcatfish