Make claude-code-review workflow configurable

[francoisferrand]

Improve the claude-code-review workflow to be configurable:

• make model configurable
• use review-pr skill from agent-hub as fallback, if not present in the repo
• configure summary mode (for agent-hub's review-pr skill)
• allow specifying marketplace branch, to simplify testing changes
• allow configuring allowedTools. These are actually not required in the workflow, as they are already in the skill;
  however keep them for compatibility with already deployed skills.

Testing changes from the agent-hub can be done quite easily, for exemple the following script in zenko uses both the workflow and agent-hub PRs. It can even be triggered manually on another PR -which is why we need the extra allowed-tools- for testing:

name: Code Review
run-name: 'Code Review for #${{ github.event.pull_request.number || inputs.pr_number }}${{ github.event.pull_request.title && format('' : {0}'', github.event.pull_request.title) }}'

on:
  pull_request:
    types: [opened, synchronize]
  workflow_dispatch:
    inputs:
      pr_number:
        description: Pull Request number to review
        required: true

jobs:
  review:
    uses: scality/workflows/.github/workflows/claude-code-review.yml@improvement/ZENKO-5260 #v2.7.0
    with:
      plugin_marketplaces: https://github.com/scality/agent-hub.git#improvement/ZENKO-5260
      allowed-tools: >-
        "Bash(gh api repos/*/content)"
    secrets:
      GCP_WORKLOAD_IDENTITY_PROVIDER: ${{ secrets.GCP_WORKLOAD_IDENTITY_PROVIDER }}
      GCP_SERVICE_ACCOUNT: ${{ secrets.GCP_SERVICE_ACCOUNT }}
      ANTHROPIC_VERTEX_PROJECT_ID: ${{ secrets.ANTHROPIC_VERTEX_PROJECT_ID }}
      CLOUD_ML_REGION: ${{ secrets.CLOUD_ML_REGION }}
      ACTIONS_APP_PRIVATE_KEY: ${{ secrets.ACTIONS_APP_PRIVATE_KEY }}

Issue: ZENKO-5260

[JBWatenbergScality]

Shall we default to 4.7 ?

[francoisferrand]

not sure : I prefer to be conservative for now, can be more easily changed/tested afterwards...

[tcarmet]

I think this one should have technically be a input, if it works great, but technically the workflow should be given all its parameter. (even if we unfortunately add an extra one here).