chore: move the command to run unit tests to makefile (#5552)
Running unit tests for a specific package in our workspace can be tricky
because some of them can only compile with specific features enabled in
their dependencies (and there isn't always an easy way to specify them
via cli flags if they are transitive dependencies).
On CI, unit tests are run using a command that skips packages that
contain heavy integration tests which are being run separately, as well
as the `query-engine-node-api` package that currently fails to compile
in test mode because it can't be linked into an executable binary that
doesn't export Node.js symbols. This command works because it compiles
all packages together with feature unification.
Since the unit tests are quick to run even for the whole workspace at
once, it's convenient to use that command locally to run unit tests
without running into conditional compilation issues.
This PR moves it to the Makefile and makes the CI workflow use the
corresponding make target.