Sidecar fix for CLR2 runtime + respect nodereuse from buildparams

[YuliiaKovalova]

Context

The introduction of sidecar taskhost functionality exposed compatibility issues with legacy scenarios and configuration settings. Node reuse was being enabled inappropriately, causing handshake failures and ignoring user preferences.
Key Issues Identified:

• CLR2 Incompatibility: Legacy MSBuildTaskHost processes running on CLR2 (.NET Framework 2.0/3.5) don't support node reuse due to process isolation and cross-process communication limitations
• Configuration Override: The system was not properly respecting the BuildParameters.EnableNodeReuse setting when users explicitly disabled node reuse through /nodereuse arg.

Changes Made

Implemented comprehensive node reuse validation to ensure node reuse is only enabled when all conditions are satisfied:

• No explicit task host factory was requested by the user
• BuildParameters.EnableNodeReuse is set to true
• Target runtime is not CLR2

[Copilot]

Pull Request Overview

This PR fixes a handshake failure in MSBuild's sidecar taskhost functionality by addressing node reuse compatibility issues with legacy task hosts. The primary issue was that parent MSBuild processes attempted to enable node reuse with CLR2 task hosts that don't support this feature.

Key Changes:

• Refactored node reuse logic by extracting complex boolean conditions into a dedicated method for better maintainability
• Added automatic detection and disabling of node reuse for legacy CLR2 runtime
• Fixed minor spelling and naming issues in comments and test method names

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/Shared/CommunicationsUtilities.cs	Fixed spelling error and added legacy runtime/architecture checks to disable node reuse
src/Build/BackEnd/Components/Communications/NodeProviderOutOfProcTaskHost.cs	Extracted node reuse logic into dedicated method with legacy scenario detection
src/Build.UnitTests/BackEnd/TaskHostFactory_Tests.cs	Fixed test method name capitalization
src/Build.UnitTests/BackEnd/ProcessIdTaskSidecar.cs	Added missing period to comment