Flaky Test: Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.actionWithoutCommitting_DoesNotLeakSession

The automated dependency reviewer bot detected a flaky test failure in PR #766.

**Failed Test:** `Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.actionWithoutCommitting_DoesNotLeakSession`
**Failure Summary:** Test actionWithoutCommitting_DoesNotLeakSession failed, likely due to session leak detection timing/flakiness.
**Workflow Run:** https://github.com/googleapis/dotnet-spanner-entity-framework/actions/runs/27980378389

**Log Excerpt:**
```text
actionWithoutCommitting_DoesNotLeakSession [14 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3055360Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.AddUniqueConstraintOperation [10 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3056470Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkMockUsingMutationsServerTests.UpdateFailsIfVersionNumberChanged [17 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3057560Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.CreateTableOperation_no_key [12 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3058550Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseOuterJoin [12 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3569410Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseStringContains [8 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3608970Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkMockUsingMutationsServerTests.VersionNumberIsAutomaticallyGeneratedOnInsertAndUpdate [12 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3610580Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.AddForeignKeyOperation_with_name [14 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3611620Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseStringConcat [7 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3613110Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkMockUsingMutationsServerTests.InsertTicketSale [28 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3614160Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.AddColumnOperation_with_maxLength_no_model [26 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3616010Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanInsertRowWithCommitTimestampAndComputedColumn [24 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.3617250Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseSpannerDateProperties [10 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4082840Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.AddPrimaryKeyOperation [12 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4105070Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.AddColumnOperation_with_defaultValueSql [15 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4106450Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.AbortedReadWriteTransaction_DoesNotLeakSession [22 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4107590Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.DropCheckConstraintOperation [11 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4108610Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseLongToString [14 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4109590Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseDateTimeAddTicks [6 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4110600Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.RenameSequenceOperation [15 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4111650Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.FindSingerAsync_ReturnsNull_IfNotFound [5 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4607210Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.CanUseSpannerNumericListCount [9 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4619730Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.Migrations.SpannerMigrationSqlGeneratorTest.CreateTableOperation [16 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4644100Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.FindSingerAsync_ReturnsInstance_IfFound [3 ms]
unit-tests (macos-latest) UNKNOWN STEP 2026-06-22T20:15:54.4677120Z Passed Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests.NestedTransactionsStartNewTransactions [6 ms]
unit-te
```

This issue was automatically created by the dependency reviewer bot.

Locate Google.Cloud.EntityFrameworkCore.Spanner.Tests.EntityFrameworkSessionLeakMockServerTests and focus on actionWithoutCommitting_DoesNotLeakSession. Re-run that test, review workflow run 27980378389, and compare its session-leak timing with the neighboring leak tests. Done means the test reliably passes without masking genuine session leaks.

Written by the indexing model from the issue text.