Removing services from API Fuzzing CI Template

What does this MR do?

Removes the serivces section and starts scanner via the script section of the CI Template. This makes it easier for users to override services to start a target container image.

Addresses #322223 (closed) Relates to #321916 (closed)

CI Template

1. This change is backwards compatible with the existing template.
2. API Fuzzing doesn't yet have a stable/latest template as the feature is < 1 yr old.
3. No new tests have been added/modified as the CI template logic hasn't changed.
4. Test project
   • Project
   • Pipeline Job
   • Project CI Template
   • 

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team