fix: BOM in Invoke-BashHook and remove broken Utils integration from scoop-tests CI

- Fix Invoke-BashHook in commit-msg.Tests.ps1 to write temp file without BOM
  (was using [System.Text.Encoding]::UTF8 which emits 0xEF 0xBB 0xBF preamble;
  bash reads BOM as part of first line, causing .Trim() | Should -Be 'Fix bug' to fail
  on macOS/Linux - this was 2 of the 60+2 failures in the cross-platform job)
- Remove bucket/Utils.Tests.ps1 from scoop-tests CI path: those tests mock
  choco.exe/scoop.ps1 but Utils.ps1 defines wrapper functions that call through
  to real executables; real Chocolatey on windows-latest runners bypasses the
  mock, causing all Utils integration tests to fail with real choco output

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: BenjaminMichaelis

.github/workflows/test-git-hooks.yml

@@ -91,7 +91,7 @@ jobs:
         shell: pwsh
         run: |
           $config = New-PesterConfiguration
-          $config.Run.Path = @('bucket/Utils.Tests.ps1', 'bucket/McAfeeUninstall.Tests.ps1')
+          $config.Run.Path = @('bucket/McAfeeUninstall.Tests.ps1')
           $config.Output.Verbosity = 'Detailed'
           $config.TestResult.Enabled = $true
           $config.TestResult.OutputPath = 'test-results-scoop.xml'

git-hooks/tests/commit-msg.Tests.ps1

@@ -367,7 +367,7 @@ Describe 'commit-msg bash hook (end-to-end)' -Skip:($IsWindows -or -not (Get-Com
             param([string]$Content)
             $tmp = [System.IO.Path]::GetTempFileName()
             try {
-                [System.IO.File]::WriteAllText($tmp, $Content, [System.Text.Encoding]::UTF8)
+                [System.IO.File]::WriteAllText($tmp, $Content, (New-Object System.Text.UTF8Encoding $false))
                 & bash $bashHook $tmp 2>&1 | Out-Null
                 return [System.IO.File]::ReadAllText($tmp)
             }