Remove bundled workflow files from leading app templates

[PujaDeshmukh17]

Removes example GitHub Actions workflow files (node.js.yml, create-test-branch.yml, and the checkout script) that were bundled inside the demo app directories for all four app variants:

Multi-tenant central space
Multi-tenant personal space
Single-tenant central space
Single-tenant personal space

These files were flagged by OrbisAI Security (cap-js/sdm#301) for a HIGH severity shell injection vulnerability — GitHub context variables (${{ github.* }}) were being interpolated directly in run: shell steps, allowing potential code execution via malicious PR titles or branch names.

Rather than patching each variant individually, the workflow files are removed entirely since they are not core to the library's functionality and shipping GitHub Actions templates inside a package creates an ongoing security maintenance burden for downstream consumers.

Single tenant integration Test: https://github.com/cap-js/sdm/actions/runs/31791434655
Multi tenant integration Test:

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist before requesting a review

• I have tested the functionality on my cloud environment.
• I have provided sufficient automated/ unit tests for the code.
• I have increased or maintained the test coverage.
• I have ran integration tests on my cloud environment.
• I have validated blackduck portal for any vulnerability after my commit.

Upload Screenshots/lists of the scenarios tested

• I have Uploaded Screenshots or added lists of the scenarios tested in description