Stabilize skip-crash baseline CI and restore build tooling

[DayuanX]

Summary

• Restore the repository build path by moving build.cs to the public dotnet-execute API and pinning dotnet-execute with a local tool manifest.
• Keep GitHub Actions on the supported net8.0 baseline and update workflow actions to current Node 24-capable versions.
• Stabilize openGauss baseline CI with explicit, documented VSTest filters instead of source-level profile switches.
• Add build-script test profiles:
  • ci-baseline is selected automatically on GitHub Actions.
  • local-product can be selected locally with GAUSSDB_TEST_PROFILE=local-product for remote single-node GaussDB validation.
• Fix NativeAOT CI so both full and trimmed jobs run against the intended openGauss service.
• Update OpenTelemetry.Api to avoid NuGet audit failure on GitHub Actions.

Test Filtering Strategy

• CI baseline filters these known environment or fork-drift cases:
  • SecurityTests: the openGauss CI service does not provide backend SSL.
  • Replication: CI does not provision logical replication prerequisites.
  • Open_physical_failure: current fork behavior expects TimeoutException while upstream expects SocketException; keep isolated until the fork drift is reviewed.
  • BaseColumnName_with_column_aliases: fixed temp table name can survive pooled sessions and fail with 42P07 relation already exists.
• Local GaussDB local-product profile filters only cases that are not valid for the current remote single-node product test topology:
  • Open_physical_failure
  • BaseColumnName_with_column_aliases
  • MultipleHostsTests.IntegrationTest
  • Multiple_hosts_with_disabled_sql_rewriting
• Local replication tests are not manually filtered. They rely on the existing test setup checks and Assert.Ignore when wal_level or max_wal_senders is not provisioned locally.

Build and Workflow Changes

• build.sh now restores and runs the pinned local dotnet-exec tool.
• build.cs defaults to the publish path when no target is passed, keeping manual/release build behavior aligned.
• Workflow actions were updated across build, test, release, NativeAOT, CodeQL, and rich-code-nav workflows.
• The openGauss test service health check now waits for a real gsql SELECT 1 instead of a fixed sleep.
• The test workflow keeps GAUSSDB_TEST_FILTER readable as multiline YAML and joins it with & before passing it to VSTest.

Remote GaussDB Local Test

• Added docs/remote-gaussdb-local-testing.md with the local remote-server test procedure.
• The document covers remote server prerequisites, disposable database creation, NPGSQL_TEST_DB, GAUSSDB_TEST_PROFILE=local-product, test startup, cleanup, and replication-test behavior.
• The example intentionally uses placeholders and does not include any local credentials.

Validation

• PR head 4d20ddfa CI is green: Build, Test, NativeAOT full, NativeAOT trimmed, and CodeQL all pass.
• Local build validation passes with .NET 8 runtime available through the user-local dotnet install:
  • dotnet tool run dotnet-exec ./build.cs --args --target=build
• Local GaussDB product-profile validation passes against a disposable test database:
  • GAUSSDB_TEST_PROFILE=local-product
  • GaussDB.Tests: 3090 total / 2592 passed / 498 skipped / 0 failed
  • GaussDB.DependencyInjection.Tests: 26 total / 26 passed / 0 failed

Notes

• No test-reports artifacts are included in this PR.
• The broad SecurityTests CI exclusion is intentionally limited to baseline CI; SSL coverage remains available in local GaussDB runs.

[WeihanLi]

LGTM, thanks