Support latest pkg:js in pkg:build_runner and pkg:build_web_compilers

[kevmoo]

Prepare both for publish

[github-actions[bot]]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:build_modules	5.0.7	ready to publish	build_modules-v5.0.7
package:build_runner	2.4.8	ready to publish	build_runner-v2.4.8
package:build_web_compilers	4.0.9	ready to publish	build_web_compilers-v4.0.9
package:build	2.4.2-wip	WIP (no publish necessary)
package:build_config	1.1.2-wip	WIP (no publish necessary)
package:build_daemon	4.0.1	already published at pub.dev
package:build_resolvers	2.4.2	already published at pub.dev
package:build_runner_core	7.2.12-wip	WIP (no publish necessary)
package:build_test	2.2.2	already published at pub.dev
package:scratch_space	1.0.3-wip	WIP (no publish necessary)

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[jakemac53]

These failures do look related so we will need to investigate