ci: added event_name schedule in client-build, rts-build, ci-test-custom-script to run them in scheduled run as well (#29724)

## Description
> added event_name schedule in client-build and rts-build to run them in
scheduled run as well

#### Type of change
- Chore (housekeeping or task changes that don't impact user perception)
>
>
## Testing
> running TBP workflow to ensure nothing is impacted. 

#### How Has This Been Tested?
- [x] TBP Run


## Checklist:
#### Dev activity
- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] PR is being merged under a feature flag


#### QA activity:
- [ ] [Speedbreak
features](https://github.com/appsmithorg/TestSmith/wiki/Guidelines-for-test-plans#speedbreakers-)
have been covered
- [ ] Test plan covers all impacted features and [areas of
interest](https://github.com/appsmithorg/TestSmith/wiki/Guidelines-for-test-plans#areas-of-interest-)
- [ ] Test plan has been peer reviewed by project stakeholders and other
QA members
- [ ] Manually tested functionality on DP
- [ ] We had an implementation alignment call with stakeholders post QA
Round 2
- [ ] Cypress test cases have been added and approved by SDET/manual QA
- [ ] Added `Test Plan Approved` label after Cypress tests were reviewed
- [ ] Added `Test Plan Approved` label after JUnit tests were reviewed


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **Chores**
  - Updated build workflows to trigger on scheduled events.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.github/workflows/build-docker-image.yml

@@ -17,7 +17,8 @@ jobs:
       github.event.pull_request.head.repo.full_name == github.repository ||
       github.event_name == 'push' ||
       github.event_name == 'workflow_dispatch' ||
-      github.event_name == 'repository_dispatch'
+      github.event_name == 'repository_dispatch' ||
+      github.event_name == 'schedule' 
     defaults:
       run:
         shell: bash

.github/workflows/ci-test-custom-script.yml

@@ -21,7 +21,8 @@ jobs:
       github.event.pull_request.head.repo.full_name == github.repository ||
       github.event_name == 'push' ||
       github.event_name == 'workflow_dispatch' ||
-      github.event_name == 'repository_dispatch'
+      github.event_name == 'repository_dispatch' ||
+      github.event_name == 'schedule' 
     defaults:
       run:
         shell: bash

.github/workflows/client-build.yml

@@ -40,7 +40,8 @@ jobs:
       github.event.pull_request.head.repo.full_name == github.repository ||
       github.event_name == 'push' ||
       github.event_name == 'workflow_dispatch' ||
-      github.event_name == 'repository_dispatch'
+      github.event_name == 'repository_dispatch' ||
+      github.event_name == 'schedule' 
     defaults:
       run:
         working-directory: app/client

.github/workflows/rts-build.yml

@@ -38,7 +38,8 @@ jobs:
       github.event.pull_request.head.repo.full_name == github.repository ||
       github.event_name == 'push' ||
       github.event_name == 'workflow_dispatch' ||
-      github.event_name == 'repository_dispatch'
+      github.event_name == 'repository_dispatch' ||
+      github.event_name == 'schedule'
 
     steps:
       # The checkout steps MUST happen first because the default directory is set according to the code base.