Updated KEP-5007 for promotion to beta

- Complete the Production Readiness Review questionnaire
- Update kep.yaml and a prod-readiness section for beta
- Add feedback from CoHDI

Signed-off-by: Tsubasa Watanabe <[email protected]>

Author: ttsuuubasa

keps/prod-readiness/sig-scheduling/5007.yaml

@@ -4,4 +4,5 @@
 kep-number: 5007
 alpha:
   approver: "@johnbelamaric"
-  
+beta:
+  approver: "@johnbelamaric"