Don't download the published version of Tact in CI

[novusnota]

Instead, we need to use the main branch and always link with it. This is important for reducing the npm download count from the usage of tact-template and Blueprint in the test suite.

That said, the command for creating a Blueprint project might have to be changed, otherwise it'll still download the Tact compiler there no matter what we do. This part is a blocker.

[novusnota]

The tact-template part should be fixed by:

• Place the Tact compiler to optionalDependencies tact-template#53
• and chore(ci): prevent downloads of Tact from npm in tact-template tests #1817