## Description
Adding a permission check for creating new datasource on generate page.
When a custom role is assigned in GAC, where the user doesn't have
access to create a new datasource, in spite of that the create new
datasource option is showed in the dropdown on generate page with data.
This is fixed with this PR.
Fixes [#22027](https://github.com/appsmithorg/appsmith/issues/22027)
## Type of change
- Bug fix (non-breaking change which fixes an issue)
## How Has This Been Tested?
> Tested it manually and it works fine.
- Manual
## Checklist:
### Dev activity
- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] PR is being merged under a feature flag
### QA activity:
- [ ] Test plan has been approved by relevant developers
- [ ] Test plan has been peer reviewed by QA
- [ ] Cypress test cases have been added and approved by either SDET or
manual QA
- [ ] Organized project review call with relevant stakeholders after
Round 1/2 of QA
- [ ] Added Test Plan Approved label after reveiwing all Cypress test
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