Run forc-unit-tests on CI in release and debug mode

[ironcev]

Description

This PR:

• changes the configuration of Forc and Forc plugins used in CI steps from debug to release.
• changes the forc-unit-tests CI step, to run the tests both in debug and release mode.

By switching to release builds, we ensure that we test the versions that are actually released, unlike the debug version. As a consequence, execution time of CI steps gets shortened. The drawback is potentially not catching issues detectable only in the debug mode, like, e.g., overflows. We will add a separate CI workflow, running nightly or on tagged versions only, that will use debug builds as explained in #7168.

Currently, we are running forc-unit-tests only in the debug mode. Compiler panics in in_language_tests, described in #7157, that happens only in release mode, shows that it is beneficial to run the unit test both in debug and release mode. Similar is with compiler panics described in #7161.

The PR also removes the explicit forc build part from those tests and leaves only the forc test part. The reasoning behind that change is, that forc test also builds the projects, indeed with tests included, but, since we currently don't support #[cfg(test)], otherwise unchanged. Running forc build in addition effectively doubles the test execution time, and the actual benefit in testing, compared to running only forc test is, in best case, negligible.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[kayagokalp]

🚀