Add @dibyom as an OWNER! 🙌

@dibyom has been contributing significant work including variable path
resource substitution #877 and
his continued work on one of our oldest and most sought after features:
conditional execution (#27)!

He has also reviewed 44+ PRs in the Pipelines repo:
https://tekton.devstats.cd.foundation/d/46/pr-reviews-by-contributor?orgId=1&var-period=d&var-repo_name=tektoncd%2Fpipeline&var-reviewers="dibyom"

OWNERS

@@ -7,6 +7,7 @@ approvers:
 - vdemeester
 - abayer
 - afrittoli
+- dibyom
 
 # Alumni ❤️
 # tejal29