RegExp script selectors included matching names even when their script bodies
were empty, unlike exact-name selection. Recursive task orchestration could
therefore dispatch tasks pulled in through dependsOn before eventually
reporting that the requested script did not exist.
Filter empty bodies at the shared script-selection boundary in both the
TypeScript CLI and pacquet, so pre-dispatch validation observes the same
missing-script semantics for exact and RegExp selectors.
Related to pnpm/pnpm#14211.