Cleanup: git config, implicit usings, test common fixes, and build props

[paulmedynski]

Summary

Housekeeping cleanup that removes unnecessary items and fixes minor issues:

• Git config: Simplified .gitattributes and .gitignore by removing redundant entries
• Implicit usings: Enabled implicit usings TestCommon project and removed unnecessary using directives from test common files
• Test common: Removed unused fixture imports and cleaned up test helper code
• Build props: Updated tools/props/AssemblyInfo.props, AssemblyRef.props, and tools/targets/RepositoryInfo.targets
• Ruleset: Minor update to ManualTesting.Tests.ruleset

Changes

• 16 files changed, 43 insertions, 344 deletions (net reduction of ~300 lines)

Checklist

• No functional changes
• No public API changes
• No breaking changes

[Copilot]

Pull request overview

Housekeeping PR focused on reducing repository noise (git config + generated files), cleaning up MSBuild metadata, and streamlining test common sources to rely more on project-level compiler settings.

Changes:

• Simplifies .gitattributes and trims .gitignore (including adding a pattern for C# language server cache files).
• Enables implicit usings in Microsoft.Data.SqlClient.TestCommon and removes now-redundant using directives / nullable pragmas from common test code.
• Cleans up build/analysis metadata files (MSBuild props/targets and the ManualTests ruleset).

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tools/targets/RepositoryInfo.targets	Reduces build log verbosity for the translated ScmRepositoryUrl message.
tools/props/AssemblyRef.props	Simplifies MSBuild project header metadata.
tools/props/AssemblyInfo.props	Simplifies MSBuild project header metadata.
src/Microsoft.Data.SqlClient/tests/ManualTests/Microsoft.Data.SqlClient.ManualTesting.Tests.ruleset	Removes Ruleset ToolsVersion metadata and normalizes formatting.
src/Microsoft.Data.SqlClient/tests/Common/Microsoft.Data.SqlClient.TestCommon.csproj	Enables <ImplicitUsings> for the TestCommon helper library.
src/Microsoft.Data.SqlClient/tests/Common/LocalAppContextSwitchesHelper.cs	Removes redundant using directives now covered by implicit usings.
src/Microsoft.Data.SqlClient/tests/Common/Fixtures/DatabaseObjects/DatabaseObject.cs	Removes redundant using directives and normalizes doc comment whitespace.
src/Microsoft.Data.SqlClient/tests/Common/Fixtures/CspCertificateFixture.cs	Removes redundant using directives now covered by implicit usings.
src/Microsoft.Data.SqlClient/tests/Common/Fixtures/ColumnMasterKeyCertificateFixture.cs	Removes redundant using directives now covered by implicit usings.
src/Microsoft.Data.SqlClient/tests/Common/Fixtures/ColumnEncryptionCertificateFixture.cs	Removes redundant using directives now covered by implicit usings.
src/Microsoft.Data.SqlClient/tests/Common/Fixtures/CertificateFixtureBase.cs	Removes redundant using directives and normalizes whitespace.
src/Microsoft.Data.SqlClient/tests/Common/Fixtures/AzureKeyVaultKeyFixtureBase.cs	Fixes malformed header comment and removes redundant using directives.
src/Microsoft.Data.SqlClient/tests/Common/DisposableArray.cs	Removes redundant using directives and file-level nullable pragma (project-level nullable applies).
src/Directory.Build.props	Simplifies MSBuild project header metadata and clarifies versioning comments.
.gitignore	Trims ignore list and adds ignore for *.lscache.
.gitattributes	Simplifies to line-ending normalization + workflow lock file attributes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.78%. Comparing base (b700269) to head (3018a56).
⚠️ Report is 19 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4301      +/-   ##
==========================================
- Coverage   66.04%   64.78%   -1.27%     
==========================================
  Files         275      279       +4     
  Lines       42976    66211   +23235     
==========================================
+ Hits        28383    42892   +14509     
- Misses      14593    23319    +8726     

Flag	Coverage Δ
CI-SqlClient	?
PR-SqlClient-Project	64.78% <ø> (?)

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.