chore: migrate to Yarn Berry (v4)#2626
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Migrate the package manager from Yarn Classic (v1) to Yarn Berry (v4) with `node-modules` linker. This replaces the custom workflow helper functions in `common.ts` with projen primitives (`project.renderWorkflowSetup()` and `github.WorkflowSteps.checkout()`) to keep CI configuration in sync with the package manager settings. Key changes: - Configure `YARN_BERRY` package manager with `node-modules` linker - Replace `--frozen-lockfile` / `--check-files` with `--immutable` - Replace `yarn version --no-git-tag-version --new-version` with Berry syntax - Add `corepack enable` before `actions/setup-node` in all workflows - Use projen primitives for checkout and workflow setup where possible
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This migrates the jsii-compiler project from Yarn Classic (v1) to Yarn Berry (v4) with the
node-moduleslinker, following the same approach used in jsii-rosetta#3622.The old
common.tsexported hardcoded helper functions (ACTIONS_CHECKOUT,ACTIONS_SETUP_NODE,YARN_INSTALL) that duplicated action versions and flags across all workflows. These have been replaced with a singleworkflowSetup()wrapper around projen'sproject.renderWorkflowSetup(), which automatically generates the correct corepack, setup-node, and install steps based on the package manager configuration. Checkout steps now usegithub.WorkflowSteps.checkout()where possible.Jobs that require custom setup-node configuration (matrix node versions, custom registry URLs) still use inline steps, since the projen primitives don't support those options.
Additionally, a 3-day cooldown has been added to the dependency upgrade workflow as supply chain protection. This is enforced at two levels:
ncu --cooldown=3filters packages during discovery, andYARN_NPM_MINIMAL_AGE_GATE=4320mblocks them atyarn installtime.By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.