fix(STONEINTG-759): remove integration e2e-tests of backed environments

[kasemAlem]

Description

Following to the feature KONFLUX-197 we want to remove the feature of ephemeral environments provisioning from integration-service.
This PR is for removing the backed namespace e2e-tests and remove related in README to unblock feature removal from CI.

Issue ticket number and link

STONEINTG-759

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added meaningful description with JIRA/GitHub issue key(if applicable), for example HASSuiteDescribe("STONE-123456789 devfile source")
• I have updated labels (if needed)

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[kasemAlem]

/test all

[sonarcloud]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[kasemAlem]

/test redhat-appstudio-e2e

[jsztuka]

lgtm

[kasemAlem]

/test redhat-appstudio-e2e

[dheerajodha]

LGTM

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dheerajodha, jsztuka

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 [dheerajodha]

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

[dheerajodha]

/lgtm

[kasemAlem]

hit the issue of failing to create PLR for components RHTAPBUGS-1111

/test redhat-appstudio-e2e