Add support to ignore request in metrics

[jan-stanek]

Proposed Changes

• Added possibility to mark request to be ignored in metrics using header K-Ignore-Metrics

[linux-foundation-easycla]

• ❌ The email address for the commit (389810a) is not linked to the GitHub account, preventing the EasyCLA check. Consult this Help Article and GitHub Help to resolve. (To view the commit's email address, add .patch at the end of this PR page's URL.) For further assistance with EasyCLA, please submit a support request ticket.

[knative-prow]

Welcome @jan-stanek! It looks like this is your first PR to knative/docs 🎉

[knative-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: jan-stanek
Once this PR has been reviewed and has the lgtm label, please assign dprotaso for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• docs/serving/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[netlify]

✅ Deploy Preview for knative ready!

Built without sensitive environment variables

Name	Link
🔨 Latest commit	389810a
🔍 Latest deploy log	https://app.netlify.com/sites/knative/deploys/67602f687fce8b00086dd5fd
😎 Deploy Preview	https://deploy-preview-6177--knative.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.