How to fix npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@3, but package-lock.json was generated for lockfileVersion@2 in npm

# Your npm version
npm --version

# Lock file version
head -5 package-lock.json
# Look for "lockfileVersion": X

echo "20" > .nvmrc

nvm use
# Now using Node 20, npm 10

# Delete old lock file
rm package-lock.json

# Regenerate
npm install

# Verify version
head -5 package-lock.json

# Force lockfileVersion 2
npm install --lockfile-version=2 --package-lock-only

lockfile-version=2

# GitHub Actions
- uses: actions/setup-node@v4
  with:
    node-version-file: '.nvmrc'

- name: Install dependencies
  run: npm ci

FROM node:20-alpine
RUN npm install -g npm@10

## Node.js Version
This project uses Node.js 20 with npm 10.
Run `nvm use` to switch to the correct version.

## Lockfile
package-lock.json uses lockfileVersion 3.
Requires npm 9+.