Prevent creation of .env file

What does this MR do?

To propagate environment variable from host to sast container, .env file is created.

Then, this .env file is analyzed by sast and may trigger TruffleHog for example.

Passing -e VARNAME to docker without definition allow to propagate environment variables without need to create the .env file.

Related Issue

Please see #209333 (closed)

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

It behaves the same.

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers