[FSSDK-12314] Remove SourceClear scan workflow due to security vulnerability

[Tamara-Barum]

Removes the SourceClear workflow that contains a dangerous curl|bash pattern, which presents risks of script injection and untrusted remote code execution in the CI/CD pipeline. This follows the same remediation approach used in the PHP SDK (optimizely/php-sdk#294).

Summary

• Removes the SourceClear scan workflow that contains a dangerous curl | bash pattern
• This pattern presents risks of script injection and untrusted remote code execution in the CI/CD pipeline
• Follows the same remediation approach used in the PHP SDK ([FSSDK-12316] [Security] Fix curl|bash vulnerability in SourceClear scan php-sdk#294)

Security Risk

The removed workflow executed:

curl -sSL https://download.sourceclear.com/ci.sh | bash -s - scan
This pattern is vulnerable because it:

Downloads and executes untrusted code without verification
Has no integrity checks
Is susceptible to DNS/MITM attacks
Test Plan
 Verify the workflow file is removed from .github/workflows/
 Confirm no other workflows depend on the source_clear job
 Check that CI/CD pipeline runs successfully without this workflow


## Issues
(https://optimizely-ext.atlassian.net/browse/FSSDK-12314)

[coveralls]

coverage: 77.733%. remained the same
when pulling c706c1e on remove-sourceclear-vulnerability
into 5af7f3b on master.

[esrakartalOpt]

LGTM 👍