security: add permissions block to workflows

[reakaleek]

Details

⚠️ This PR was created by an automated tool. Please review the changes carefully. ⚠️

We want to set the default permissions for workflows to read-only for contents.
This is a security measure to prevent accidental changes to the repository.

This change adds a top-level permissions block to all workflows in the .github/workflows directory.

permissions:
  contents: read

In some cases workflows might need more permissions than just contents: read.
Please checkout this branch and add the necessary permissions to the workflows.

If your workflow uses a Personal Access Token (PAT), we can still add the permissions block,
but it will not have any effect.

Merging this PR as is might cause workflows that need more permissions to fail.

If there are any questions, please reach out to the @elastic/observablt-ci

[trentm]

I think I got review incorrect on this. This workflow needs write permission to the issue/PR to add a label. I'm not sure if that is being limited by this permissions: ... addition.

Recently two PRs have had this labeler workflow fail:
https://github.com/elastic/apm-agent-nodejs/actions/runs/8042135103/job/22024012622?pr=3882
https://github.com/elastic/apm-agent-nodejs/actions/runs/8042141883/job/21962393814?pr=3883

Run AlexanderWert/issue-labeler@v2.3
  with:
    repo-token: ***
    configuration-path: .github/labeler-config.yml
    enable-versioned-regex: 0
  env:
    MY_GITHUB_TOKEN: ***
Adding labels agent-nodejs to issue #3882
/home/runner/work/_actions/AlexanderWert/issue-labeler/v2.3/node_modules/@octokit/request/dist-node/index.js:66
        const error = new requestError.RequestError(message, status, {
                      ^

RequestError [HttpError]: Resource not accessible by integration
    at /home/runner/work/_actions/AlexanderWert/issue-labeler/v2.3/node_modules/@octokit/request/dist-node/index.js:66:23
    at processTicksAndRejections (node:internal/process/task_queues:96:5) {
  status: 403,
  headers: {
    'access-control-allow-origin': '*',
    'access-control-expose-headers': 'ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Resource, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, X-GitHub-SSO, X-GitHub-Request-Id, Deprecation, Sunset',
    connection: 'close',
    'content-encoding': 'gzip',
    'content-security-policy': "default-src 'none'",
    'content-type': 'application/json; charset=utf-8',
    date: 'Tue, 27 Feb 2024 10:12:23 GMT',
    'referrer-policy': 'origin-when-cross-origin, strict-origin-when-cross-origin',
    server: 'GitHub.com',
    'strict-transport-security': 'max-age=31536000; includeSubdomains; preload',
    'transfer-encoding': 'chunked',
    vary: 'Accept-Encoding, Accept, X-Requested-With',
    'x-accepted-github-permissions': 'issues=write; pull_requests=write',
    'x-content-type-options': 'nosniff',
    'x-frame-options': 'deny',
    'x-github-api-version-selected': '2022-11-28',
    'x-github-media-type': 'github.v3; format=json',
    'x-github-request-id': 'D084:4803:180CFA2:2FA3CB1:65DDB587',
    'x-ratelimit-limit': '15000',
    'x-ratelimit-remaining': '14998',
    'x-ratelimit-reset': '1709032343',
    'x-ratelimit-resource': 'core',
    'x-ratelimit-used': '2',
    'x-xss-protection': '0'
  },
  request: {
    method: 'POST',
    url: 'https://api.github.com/repos/elastic/apm-agent-nodejs/issues/3882/labels',
    headers: {
      accept: 'application/vnd.github.v3+json',
      'user-agent': 'octokit.js/16.43.2 Node.js/16.20.2 (Linux 6.2; x64)',
      authorization: 'token [REDACTED]',
      'content-type': 'application/json; charset=utf-8'
    },
    body: '{"labels":["agent-nodejs"]}',
    request: {
      hook: [Function: bound bound register],
      validate: {
        issue_number: { required: true, type: 'integer' },
        labels: { required: true, type: 'string[]' },
        number: { alias: 'issue_number', deprecated: true, type: 'integer' },
        owner: { required: true, type: 'string' },
        repo: { required: true, type: 'string' }
      }
    }
  },
  documentation_url: 'https://docs.github.com/rest/issues/labels#add-labels-to-an-issue'
}

I don't know that this is about this change, but it seems related.