Update documentation for DS MAVEN_CLI_OPTS

What does this MR do?

This MR updates the documentation for MAVEN_CLI_OPTS in dependency scanning to remove direct reference to which phase the variable is used in (it is now used in all phases) and to indicate what the variable defaults are.

Related issue: #37963 (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

This is just documentation.

Security

Not applicable.