chore: use release name as etcd namespace

[atzoum]

🔒 Scanned for secrets using gitleaks 8.30.0

Description

Using RELEASE_NAME instead of WORKSPACE_NAMESPACE, since all other components rely on RELEASE_NAME for namespacing etcd keys

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.69%. Comparing base (67befa5) to head (bfb0211).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6707      +/-   ##
==========================================
- Coverage   80.08%   79.69%   -0.40%     
==========================================
  Files         565      566       +1     
  Lines       63325    63335      +10     
==========================================
- Hits        50713    50472     -241     
- Misses       9617     9878     +261     
+ Partials     2995     2985      -10     

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