chore: switch to mise for dev environment

.github/workflows/ci.yaml

@@ -25,9 +25,7 @@ jobs:
           --health-retries 5
     steps:
       - uses: actions/checkout@v6
-      - uses: actions/setup-node@v6
-        with:
-          node-version-file: package.json
+      - uses: jdx/mise-action@v2
       - run: npm ci
       - run: npm run ci
       - uses: codecov/codecov-action@v6
@@ -49,10 +47,7 @@ jobs:
           --health-retries 5
     steps:
       - uses: actions/checkout@v6
-      - uses: actions/setup-node@v6
-        with:
-          node-version-file: package.json
-      - uses: oven-sh/setup-bun@v2
+      - uses: jdx/mise-action@v2
       - run: npm ci
       - run: bun run ci:bun
   # https://commitlint.js.org/guides/ci-setup.html
@@ -62,9 +57,7 @@ jobs:
       - uses: actions/checkout@v6
         with:
           fetch-depth: 0
-      - uses: actions/setup-node@v6
-        with:
-          node-version-file: package.json
+      - uses: jdx/mise-action@v2
       - run: npm install -D @commitlint/cli @commitlint/config-conventional
       - name: Validate current commit (last commit) with commitlint
         if: github.event_name == 'push'

.github/workflows/pkg-pr-new.yaml

@@ -11,9 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: actions/setup-node@v6
-        with:
-          node-version-file: package.json
+      - uses: jdx/mise-action@v2
       - run: npm ci
       - run: npm run build
       - run: >

CONTRIBUTING.md

@@ -21,3 +21,11 @@ why it belongs in OpenWorkflow. The core team will help confirm direction before
 any PRs start.
 
 PRs that skip these steps may be closed.
+
+## Development environment
+
+This repo uses [mise](https://mise.jdx.dev/) to manage the Node and Bun versions
+used for development. Once you have mise installed, run `mise trust` followed by
+`mise install` from the repo root to install the versions configured in
+`mise.toml`. The GitHub Actions workflows install those versions via
+`jdx/mise-action`.

mise.toml

@@ -0,0 +1,3 @@
+[tools]
+node = "lts"
+bun = "1"