chore(deps): update dependency polyfill to v10

[thomhurst]

This PR contains the following updates:

Package	Type	Update	Change
Polyfill	nuget	major	9.24.1 → 10.0.0

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Release Notes

SimonCropp/Polyfill (Polyfill)

v10.0.0

Compare Source

• #​515 Add new static extension polyfills using C# 14 syntax
• #​516 Consider migrating Directory polyfills to extension(Directory) syntax
• #​518 Add IndexOfAnyExcept and LastIndexOfAnyExcept
• #​519 Migrate Directory polyfills to extension(Directory) syntax

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Configuration

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This PR has been generated by Renovate Bot.

[codacy-production]

Up to standards ✅

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[claude]

Code Review: Polyfill v9.24.1 → v10.0.0

Summary: Straightforward major-version dependency bump of the Polyfill source-generator package, touching a single line in TUnit.Core/TUnit.Core.targets.

Analysis

The change is safe. Here's why:

1. C# 14 syntax in v10.0.0 — The breaking change that warrants a major version is the migration of Directory polyfills to the new extension(Directory) syntax (C# 14). TUnit already has LangVersion = preview, so this compiles fine.

2. Compile-time only, no runtime impact — The package is included as compile; analyzers only with PrivateAssets=all, so no runtime binary is affected. There is no risk of a deploy-time regression.

3. Narrow injection scope — The _TUnitNeedsPolyfill condition gates injection to netstandard2.0, netstandard2.1, and .NETFramework targets only. TUnit's own multi-targets (net8.0;net9.0;net10.0) are unaffected; the polyfill is only injected for downstream consumers on legacy frameworks.

4. No breaking API changes — The release notes list only additive changes: new IndexOfAnyExcept/LastIndexOfAnyExcept polyfills and the internal syntax migration. Nothing removed.

5. Automerge is already enabled — Standard Renovate dependency-update flow.

No concerns. LGTM ✓

[claude]

Code Review Update

No changes since the previous review — the diff remains a single-line version bump in TUnit.Core/TUnit.Core.targets.

All prior analysis still applies:

• Compile-time only — no runtime impact; package is injected with PrivateAssets=all.
• C# 14 syntax in v10.0.0 (the extension(Directory) migration) is compatible because LangVersion = preview is already set project-wide.
• Additive changes only — new IndexOfAnyExcept/LastIndexOfAnyExcept polyfills; nothing removed.
• Narrow scope — polyfill injection is gated to netstandard2.0, netstandard2.1, and .NETFramework targets; TUnit's own net8.0;net9.0;net10.0 builds are unaffected.

LGTM. Safe to merge.