Remove zed dependency from docs_preprocessor (#45130)

Closes #ISSUE

Uses the existing `--dump-all-actions` arg on the Zed binary to generate
an asset of all of our actions so that the `docs_preprocessor` can
injest it, rather than depending on the Zed crate itself to collect all
action names

Release Notes:

- N/A *or* Added/Fixed/Improved ...

---------

Co-authored-by: Zed Zippy <234243425+zed-zippy[bot]@users.noreply.github.com>

tooling/xtask/src/tasks/workflows/run_tests.rs

@@ -448,6 +448,7 @@ fn check_docs() -> NamedJob {
                 lychee_link_check("./docs/src/**/*"), // check markdown links
             )
             .map(steps::install_linux_dependencies)
+            .add_step(steps::script("./script/generate-action-metadata"))
             .add_step(install_mdbook())
             .add_step(build_docs())
             .add_step(