feat: yarn -> pnpm

[stephenlago99]

Replace yarn with pnpm to improve the dependency installation speeds.

[stephenlago99]

Converted this to a draft since some tasks with more priority came in.

To wrap this up, only the following need to be done:

• Fix .github/workflows/cypress.ts by caching the Cypress binary between runs (currently it's failing because it can't find the binary)

Suggestion:

      - name: Cache Cypress binary
        uses: actions/cache@v3
        with:
          path: ~/.cache/Cypress
          key: cypress-binary-${{ hashFiles('pnpm-lock.yaml') }}
          restore-keys: |
            cypress-binary-

• Fix .github/workflows/codegen.ts by waiting until the graphql endpoint is up (currently it's failing because the install takes just a few seconds and when codegen is ran the API is not up yet)

Suggestion:

      - name: Launch API
        run: docker compose -f ./ci/docker-compose.ci.yml --env-file ./.env up -d api

      - name: Wait for API to be ready
        run: |
          timeout 60s bash -c '
          until curl -s -f -o /dev/null "http://localhost:3000/graphql"; do
            echo "Waiting for API to be ready..."
            sleep 2
          done
          '