Remove observability from alpha1

[tataruty]

Proposed changes

Problem:
We need to remove v1alpha1 version of the Observability API in the future. We are supporting a newer version v1alpha2 for Observability API now.
#2986 to support the newer version.

Solution: Remove observability from v1alpha1.

Testing: Functional and unit tests

Closes #2767

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

Remove deprecated v1alpha1 Observability API

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.07%. Comparing base (64a5b2c) to head (81b7e7a).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4215      +/-   ##
==========================================
- Coverage   86.10%   86.07%   -0.03%     
==========================================
  Files         131      131              
  Lines       14162    14162              
  Branches       35       35              
==========================================
- Hits        12194    12190       -4     
- Misses       1766     1768       +2     
- Partials      202      204       +2     

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[ciarams87]

@tataruty We should add a release note too that we removed this deprecated API

[salonichf5]

Can we update the description on what happens when we use that API version? Could you check the upgrade process? For example if a user is using this version and we delete it -- what does the user see? or does it get automatically upgraded?

Looks good to me otherwise