Configure OIDC end_session_endpoint (backport #11218)

[mergify]

Proposed Changes

Implements feature request #11103

Doc's PR -> rabbitmq/rabbitmq-website#1925

Types of Changes

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• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
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• Cosmetic change (whitespace, formatting, etc)
• Build system and/or CI

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• I have added tests that prove my fix is effective or that my feature works
• All tests pass locally with my changes
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---

This is an automatic backport of pull request #11218 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 72ab194 has failed:

On branch mergify/bp/v3.13.x/pr-11218
Your branch is up to date with 'origin/v3.13.x'.

You are currently cherry-picking commit 72ab1944bf.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   deps/oauth2_client/include/oauth2_client.hrl
	modified:   deps/oauth2_client/test/system_SUITE.erl
	modified:   deps/rabbitmq_auth_backend_oauth2/priv/schema/rabbitmq_auth_backend_oauth2.schema
	modified:   deps/rabbitmq_auth_backend_oauth2/test/config_schema_SUITE_data/rabbitmq_auth_backend_oauth2.snippets
	modified:   deps/rabbitmq_management/Makefile
	modified:   deps/rabbitmq_management/priv/www/js/oidc-oauth/helper.js
	modified:   deps/rabbitmq_management/selenium/package.json
	modified:   deps/rabbitmq_management/selenium/test/basic-auth/ac-management.js
	modified:   deps/rabbitmq_management/selenium/test/basic-auth/env.docker.proxy
	modified:   deps/rabbitmq_management/selenium/test/basic-auth/env.local.proxy
	modified:   deps/rabbitmq_management/selenium/test/pageobjects/BasePage.js
	modified:   deps/rabbitmq_management/src/rabbit_mgmt_wm_auth.erl
	modified:   deps/rabbitmq_management/test/rabbit_mgmt_wm_auth_SUITE.erl

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   deps/oauth2_client/src/oauth2_client.erl

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally