chore: add ashishdhingra to contribution/core label (#31165)

add `ashishdhingra` into the list of `contribution/core` label

### Issue # (if applicable)

Closes #<issue number here>.

### Reason for this change



### Description of changes



### Description of how you validated changes



### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

.mergify.yml

@@ -11,7 +11,7 @@ pull_request_rules:
       label:
         add: [ contribution/core ]
     conditions:
-      - author~=^(rix0rrr|iliapolo|otaviomacedo|kaizencc|comcalvi|TheRealAmazonKendra|vinayak-kukreja|mrgrain|pahud|cgarvis|kellertk|HBobertz|sumupitchayan|SankyRed|udaypant|colifran|scanlonp|mikewrighton|moelasmar|paulhcsun|awsmjs|evgenyka|GavinZZ|aaythapa|xazhao|ConnorRobertson|ssenchenko|gracelu0|jfuss|SimonCMoore|shikha372|kirtishrinkhala|godwingrs22|bergjaak|samson-keung|IanKonlog|Leo10Gama|scorbiere)$
+      - author~=^(rix0rrr|iliapolo|otaviomacedo|kaizencc|comcalvi|TheRealAmazonKendra|vinayak-kukreja|mrgrain|pahud|ashishdhingra|cgarvis|kellertk|HBobertz|sumupitchayan|SankyRed|udaypant|colifran|scanlonp|mikewrighton|moelasmar|paulhcsun|awsmjs|evgenyka|GavinZZ|aaythapa|xazhao|ConnorRobertson|ssenchenko|gracelu0|jfuss|SimonCMoore|shikha372|kirtishrinkhala|godwingrs22|bergjaak|samson-keung|IanKonlog|Leo10Gama|scorbiere)$
       - -label~="contribution/core"
   - name: automatic merge
     actions: