Replace rust-condition-script-cargo_make_current_task_initial_makefile_directory-substitution plugin with new cargo make feature

[wmmc88]

          With resolution of https://github.com/sagiegurari/cargo-make/issues/1081, this plugin may be no longer needed. This can be addressed in a followup

Originally posted by @wmmc88 in #143 (comment)

[svasista-ms]

@wmmc88, I'm working on this issue. I'll raise a PR after #186 is merged.

[wmmc88]

@svasista-ms On closer inspection, I believe this task is blocked by sagiegurari/cargo-make#1132 merging. While sagiegurari/cargo-make#1081 was resolved, it still fails to expand the args based of local testing. sagiegurari/cargo-make#1132 should fix that.

[wmmc88]

@svasista-ms you should be unblocked now