fix(query-orchestrator): Table used cache should not be used for unions

[ovr]

We don't need to cache them or mark as used in cache store, because it's single tables. Caching such keys result in huge memory usage, we can call it as memory leak.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 54.57%. Comparing base (2986f19) to head (433f273).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...y-orchestrator/src/orchestrator/PreAggregations.ts	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #10192      +/-   ##
==========================================
- Coverage   54.57%   54.57%   -0.01%     
==========================================
  Files         217      217              
  Lines       17018    17019       +1     
  Branches     3475     3476       +1     
==========================================
  Hits         9288     9288              
- Misses       7229     7230       +1     
  Partials      501      501              

Flag	Coverage Δ
cube-backend	54.57% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[KSDaemon]

👍🏻 Cool!