RHOAIENG-1373 - Remove the individual build and test pipelines

[MarianMacik]

JIRA: RHOAIENG-1373

Description

• Build & Test pipelines have been moved under the /pipelines/tekton/obsolete/ directory with a separate README file.
• aiedge-e2e README parts were moved to the parent README under the /pipelines/tekton/ directory and the original README was removed.
• Minor improvements to the secret naming and various other documentation fixes.

How Has This Been Tested?

It's mainly documentation update, so no need for any automated testing.

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: MarianMacik

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• OWNERS [MarianMacik]

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[MarianMacik]

I left a few questions because I wasn't sure @LaVLaS.

Also, in case you would like to have the old pipelines somewhere else (or use deprecated instead of obsolete), just tell.

[MarianMacik]

@LaVLaS all comments addressed.

[LaVLaS]

/lgtm

Looks great! I updated the merge conflict.