Don't set process priority unless instructed to

[Tyrrrz]

Closes #279

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Project coverage is 95.23%. Comparing base (7676d77) to head (ff973a1).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
CliWrap/Utils/ProcessEx.cs	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #282      +/-   ##
==========================================
- Coverage   95.38%   95.23%   -0.16%     
==========================================
  Files          48       48              
  Lines        1193     1197       +4     
  Branches       86       86              
==========================================
+ Hits         1138     1140       +2     
- Misses         35       37       +2     
  Partials       20       20              

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[Copilot]

PR Overview

This pull request ensures that process priority is only set when explicitly instructed, addressing issue #279. Key changes include:

• Rearranging the process startup sequence and error message construction in ProcessEx.cs.
• Adding a null check for ResourcePolicy.Priority and updating the exception message in Command.Execution.cs.
• Modifying ResourcePolicyBuilder.cs and ResourcePolicy.cs to support a nullable priority, preventing unintentional process priority settings.

Reviewed Changes

File	Description
CliWrap/Utils/ProcessEx.cs	Moved start time recording and custom configuration post try-catch.
CliWrap/Command.Execution.cs	Added a null check for priority and updated the error message wording.
CliWrap/Builders/ResourcePolicyBuilder.cs	Updated priority type to nullable and adjusted setter accordingly.
CliWrap/ResourcePolicy.cs	Allowed a nullable priority by updating the default value and accessor.

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

Comments suppressed due to low confidence (1)

CliWrap/Command.Execution.cs:320

• [nitpick] Consider adding braces for the if-statement to improve clarity and reduce potential maintenance issues.

if (ResourcePolicy.Priority is not null)