Deprecate and remove AJP support

[rikatz]

What this PR does / why we need it:

Deprecate AJP as a valid backend protocol

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• CVE Report (Scanner found CVE and adding report)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

fixes: #10098

[netlify]

✅ Deploy Preview for kubernetes-ingress-nginx ready!

Name	Link
🔨 Latest commit	93458ec
🔍 Latest deploy log	https://app.netlify.com/sites/kubernetes-ingress-nginx/deploys/649f30d1dfc4e10008c5ecf9
😎 Deploy Preview	https://deploy-preview-10158--kubernetes-ingress-nginx.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.

[k8s-ci-robot]

This issue is currently awaiting triage.

If Ingress contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[rikatz]

/hold
We are in the middle of a release, let's not merge this

[rikatz]

/hold cancel

[tao12345666333]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: rikatz, tao12345666333

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [rikatz,tao12345666333]

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

[strongjz]

/cherry-pick release-1.9

[k8s-infra-cherrypick-robot]

@strongjz: #10158 failed to apply on top of branch "release-1.9":

Applying: Deprecate and remove AJP support
Using index info to reconstruct a base tree...
M	docs/e2e-tests.md
M	docs/user-guide/nginx-configuration/annotations.md
M	images/nginx/rootfs/build.sh
M	internal/ingress/annotations/backendprotocol/main.go
M	internal/ingress/controller/template/template.go
M	internal/ingress/controller/template/template_test.go
M	rootfs/etc/nginx/template/nginx.tmpl
M	test/e2e/annotations/backendprotocol.go
Falling back to patching base and 3-way merge...
Auto-merging rootfs/etc/nginx/template/nginx.tmpl
Auto-merging internal/ingress/controller/template/template_test.go
Auto-merging internal/ingress/controller/template/template.go
Auto-merging docs/e2e-tests.md
CONFLICT (content): Merge conflict in docs/e2e-tests.md
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Deprecate and remove AJP support
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherry-pick release-1.9

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.