[OPIK-8230] [BE] fix: scope the trace delete mutation to the batch's own partitions - #8131

   26 files  ±    0     26 suites  ±0   4m 19s ⏱️ - 5m 39s
1 900 tests  -     3  1 899 ✅  -     3  1 💤 ±0  0 ❌ ±0 
  259 runs   - 1 597    258 ✅  - 1 597  1 💤 ±0  0 ❌ ±0 

Results for commit 72a67bc. ± Comparison against earlier commit 4b1d936.