devops: read workspace crate names from cargo metadata --no-deps

[prql-bot]

task test-rust-api has silently stopped excluding prqlc-parser, and task build-each-crate passes Cargo package IDs where it means package names. Both read the workspace's crates with:

cargo metadata --format-version=1 | jq -r '.workspace_members[] | split(" ")[0]'

workspace_members used to hold "<name> <version> (<source>)", so splitting on the space took the name. Cargo now emits opaque package IDs with no space in them, so the split is a no-op and each entry comes out as e.g. path+file:///…/prqlc/prqlc-parser#0.13.15.

build-each-crate still works, because Cargo accepts a full package-ID spec after -p. test-rust-api does not: its without (splitLines .PACKAGES) "prqlc-parser" compares against the plain name, which no longer appears anywhere in the list, so the crate the task's summary says it excludes is tested anyway.

Reading .packages[].name under --no-deps gives the plain names directly — --no-deps restricts .packages to the workspace's own crates, which is what workspace_members was being used for.

No changelog entry: this is dev tooling with no user-facing effect. Neither task runs in CI — build-each-crate is reached only through task build-all, and nothing invokes test-rust-api.

Rendered commands, before and after

Before, from task --dry test-rust-api:

cargo test  -p=path+file:///…/prqlc/bindings/elixir/native/prql#0.13.15  -p=path+file:///…/prqlc/prqlc#0.13.15  -p=path+file:///…/prqlc/prqlc-parser#0.13.15  …

After:

cargo test  -p=prql  -p=prqlc  -p=prql-java  -p=prqlc-js  -p=prqlc-c  -p=prqlc-python  -p=prqlc-macros  -p=compile-files  -p=mdbook-prql

prqlc-parser is absent from the second, as the task's summary intends.