Remove deprecated fields and messages

[vepatel]

This epic will be used to track all the tasks/issues which introduce a flag or functionality requiring some sort of depreciation in upcoming releases

### Tasks
- [ ] https://github.com/nginxinc/kubernetes-ingress/issues/5260
- [ ] Remove controller.readOnlyRootFilesystem in 3 major releases post 3.5.
- [x] Remove section regarding `external references` in our [app-protect-waf integration](https://docs.nginx.com/nginx-ingress-controller/installation/integrations/app-protect-waf/installation/#makefile-targets) docs
- [ ] Reomove section regarding ` waf.securityLog` field for the `waf` policy and update example resource in [configuration/policy-resource/#waf](https://docs.nginx.com/nginx-ingress-controller/configuration/policy-resource/#waf)
- [x] https://docs.nginx.com/nginx-ingress-controller/configuration/global-configuration/command-line-arguments/#-inlcude-year
- [ ] https://github.com/nginxinc/kubernetes-ingress/issues/5776
- [ ] https://github.com/nginxinc/kubernetes-ingress/issues/5777
- [ ] Deprication of [NGINX OpenTracing](https://docs.nginx.com/nginx/admin-guide/dynamic-modules/opentracing/) module as or R32 - Will last up to R34 - Will be **FULLY REMOVED** in R35) [R32 Release notes](https://docs.nginx.com/nginx/releases/#r32:~:text=LTS%2C%2024.04%20LTS-,Notes,-%3A)

[github-actions[bot]]

Hi @vepatel thanks for reporting!

Be sure to check out the docs and the Contributing Guidelines while you wait for a human to take a look at this :slightly_smiling_face:

Cheers!