enhance: test on Windows and fix what it found (#1348)

Adds a weekly and on-demand workflow that runs the cross-compiled tests on Windows Server 2025 Core in a [dockur/windows](https://github.com/dockur/windows) QEMU VM, and fixes the Windows bugs it found in host and UNC paths, env handling, shell quoting, post-task scripts, health checks, checkout, action symlinks, step summaries, Git client certificates and docker mode from a Windows host.

Host-mode steps now emit UTF-8, `bash` falls back to Git's bash instead of the WSL launcher, the runner can run as a native Windows service, steps can keep background helpers with `RUNNER_TRACKING_ID`, and Windows arm64 binaries are released.

Fixes: https://gitea.com/gitea/runner/issues/1339
Fixes: https://gitea.com/gitea/runner/issues/637
Fixes: https://gitea.com/gitea/runner/issues/1172
Fixes: https://gitea.com/gitea/runner/issues/347
Reviewed-on: https://gitea.com/gitea/runner/pulls/1348
Reviewed-by: bircni <[email protected]>

scripts/test-windows-setup.ps1

@@ -0,0 +1,29 @@
+$ErrorActionPreference = 'Stop'
+$ProgressPreference = 'SilentlyContinue'
+$shared = '\\host.lan\Data'
+try {
+    Write-Output '==> Setting up Windows'
+    Set-ItemProperty HKLM:\SYSTEM\CurrentControlSet\Control\FileSystem LongPathsEnabled 1
+    foreach ($tool in @(
+            @('git.7z.exe', 'https://github.com/git-for-windows/git/releases/download/v2.56.0.windows.3/PortableGit-2.56.0.3-64-bit.7z.exe', '4fc27b779829a36df77911e3f4dea09c66c790dd6c5f7dfa3b6a5479f1fe354f'),
+            @('node.zip', 'https://nodejs.org/dist/v24.22.1/node-v24.22.1-win-x64.zip', 'd2046d28c2c3dcd211ac5145c0bf30e2047ef9dfb306693c8c6e2eccd8b95fa5'),
+            @('pwsh.zip', 'https://github.com/PowerShell/PowerShell/releases/download/v7.6.8/PowerShell-7.6.8-win-x64.zip', 'b9f074f923c499b51ec99d313da8e9ae90d17a9f3adf00c73d6189f34d908528'))) {
+        Write-Output "==> Downloading $($tool[1])"
+        Invoke-WebRequest -UseBasicParsing $tool[1] -OutFile "$env:TEMP\$($tool[0])"
+        if ((Get-FileHash "$env:TEMP\$($tool[0])").Hash -ne $tool[2]) { throw "checksum mismatch for $($tool[1])" }
+    }
+    Write-Output '==> Extracting git, node and pwsh'
+    New-Item -ItemType Directory C:\pwsh | Out-Null
+    @(
+        Start-Process "$env:TEMP\git.7z.exe" -ArgumentList '-oC:\git', '-y' -PassThru
+        Start-Process tar.exe -ArgumentList '-xf', "$env:TEMP\node.zip", '-C', 'C:\' -PassThru -NoNewWindow
+        Start-Process tar.exe -ArgumentList '-xf', "$env:TEMP\pwsh.zip", '-C', 'C:\pwsh' -PassThru -NoNewWindow
+    ) | Wait-Process
+    Rename-Item (Resolve-Path C:\node-*-win-x64).Path C:\node
+    $env:Path = "C:\git\cmd;C:\git\bin;C:\pwsh;C:\node;$env:Path"
+    Get-Command git, bash, node, pwsh | Out-Null
+} catch {
+    $_ | Out-String | Tee-Object "$shared\error.txt"
+    Set-Content "$shared\exitcode" 1
+    exit 1
+}