Add eas.json contents as step output

[thgh]

Description of the feature

The action could output the eas.json contents so it can be reused by other steps

Motivation

I would like to use expo publish to the production release channel

Additional context

This is my current workaround:

      - name: 🏗 Setup Expo and EAS
        uses: expo/expo-github-action@v7

      - name: 📦 Install dependencies
        run: yarn install

      - name: 🏗 Release channel
        uses: sergeysova/jq-action@v2
        id: releaseChannel
        with:
          cmd: 'jq .build.production.releaseChannel eas.json -r'

      - name: 🚀 Publish app
        run: expo publish --non-interactive --release-channel=${{ steps.releaseChannel.outputs.value }}

Suggested workflow:

      - name: 🏗 Setup Expo and EAS
        uses: expo/expo-github-action@v7
        id: expo

      - name: 📦 Install dependencies
        run: yarn install

      - name: 🚀 Publish app
        run: expo publish --non-interactive --release-channel=${{ steps.expo.eas.build.production.releaseChannel }}