Code Tidy: Remove package validation suppression files

[AndyButland]

Description

Now that we are working towards the v18 major release, the CompatibilitySuppressions.xml baseline files saved during the v17 lifetime to permit breaking changes in package validation are no longer relevant and have been removed.

Note that EnablePackageValidation remains false in Directory.Build.props (see existing TODO (V18) comment) and will be re-enabled once 18.0.0 is released, at which point a fresh baseline can be generated.

[claude]

Claude finished @AndyButland's task in 1m 18s —— View job

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PR Review

Target: origin/v18/dev · Based on commit: 5c5eccf1 · Skipped: 0 noise files · Classified as: Config-only

Removes four v17-era CompatibilitySuppressions.xml baseline files that suppressed package validation diagnostics accumulated during the v17 release cycle — no longer relevant now that the v18 major baseline is being established.

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No issues found. This is a clean deletion of stale configuration artifacts. With EnablePackageValidation=false in Directory.Build.props (and the existing TODO (V18) comment to re-enable it post-release), removing these files has no effect on the current build and correctly sets up a clean state for the v18 baseline.

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Approved

This looks good to be merged as-is, but please do a manual sanity check and testing before merging.

[Copilot]

Pull request overview

This PR removes legacy CompatibilitySuppressions.xml baseline files that were used to suppress .NET package validation diagnostics during the v17 lifecycle, aligning the repo with the move toward the v18 major release and reducing maintenance noise.

Changes:

• Removed v17-era package validation suppression baselines from src/ and tests/.
• Eliminated now-empty suppression files that no longer provided value.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
tests/Umbraco.Tests.Integration/CompatibilitySuppressions.xml	Removed historical package validation suppressions for integration test assembly.
tests/Umbraco.Tests.Common/CompatibilitySuppressions.xml	Removed empty suppression baseline file.
src/Umbraco.Core/CompatibilitySuppressions.xml	Removed empty suppression baseline file.
src/Umbraco.Cms.Api.Management/CompatibilitySuppressions.xml	Removed historical package validation suppressions for Management API package.

[Zeegaan]

Looks good to me 😁