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

   19 files  ±0     19 suites  ±0   7m 46s ⏱️ -20s
1 690 tests ±0  1 690 ✅ ±0  0 💤 ±0  0 ❌ ±0 
1 602 runs  ±0  1 602 ✅ ±0  0 💤 ±0  0 ❌ ±0 

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