Update OWNERS_ALIASES (#39)

Issue #, if available:

Description of changes:
- remove rushmash91

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Author: knottnt

OWNERS_ALIASES

@@ -4,10 +4,10 @@ aliases:
   core-ack-team:
     - a-hilaly
     - knottnt
-    - rushmash91
     - michaelhtm
 
   # emeritus-core-ack-team:
+  #  - rushmash91
   #  - jaypipes
   #  - mhausenblas
   #  - RedbackThomson