[PATCH v2 1/4] ci(gitlab,windows): provision GNU Rust for SDK-based MinGW builds

["Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>]

From: Johannes Schindelin <johannes.schindelin@gmx.de>

The minimal Git for Windows SDK already supplies Git and GCC. The MinGW
Makefile build needs the Rust toolchain that targets GCC (as opposed to
the more common MSVC one), not another Git installation or Meson.

Prepare the `install-dependencies.ps1` script to be able to install the
GCC-targeting Rust toolchain.

Assisted-by: GPT-6
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 ci/install-dependencies.ps1 | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/ci/install-dependencies.ps1 b/ci/install-dependencies.ps1
index e3b367fa54..8c68fb0cfc 100755
--- a/ci/install-dependencies.ps1
+++ b/ci/install-dependencies.ps1
@@ -1,5 +1,6 @@
 param(
-    [string]$DownloadDirectory = '.dependencies'
+    [string]$DownloadDirectory = '.dependencies',
+    [switch]$Mingw
 )
 
 $ErrorActionPreference = 'Stop'
@@ -41,6 +42,17 @@ function Invoke-Installer {
     }
 }
 
+$rustTarget = if ($Mingw) { 'gnu' } else { 'msvc' }
+$rustMsi = Get-Installer "rust-$rustTarget.msi" (
+    "https://static.rust-lang.org/dist/" +
+    "rust-$RustVersion-x86_64-pc-windows-$rustTarget.msi")
+Invoke-Installer msiexec.exe @('/i', $rustMsi, 'INSTALLDIR=C:\Rust',
+    'ADDLOCAL=Rustc,Cargo,Std', '/quiet', '/norestart')
+
+if ($Mingw) {
+    return
+}
+
 $gitAssetVersion = $GitVersion -replace '\.windows\.\d+$', ''
 $gitInstaller = Get-Installer "Git-Installer.exe" `
     "https://github.com/git-for-windows/git/releases/download/v$GitVersion/PortableGit-$gitAssetVersion-64-bit.7z.exe"
@@ -49,7 +61,3 @@ Invoke-Installer $gitInstaller @('-y', '-o"C:\Program Files\Git"')
 $mesonMsi = Get-Installer "meson.msi" `
     "https://github.com/mesonbuild/meson/releases/download/$MesonVersion/meson-$MesonVersion-64.msi"
 Invoke-Installer msiexec.exe @('/i', $mesonMsi, 'INSTALLDIR=C:\Meson', '/quiet', '/norestart')
-
-$rustMsi = Get-Installer "rust.msi" `
-    "https://static.rust-lang.org/dist/rust-$RustVersion-x86_64-pc-windows-msvc.msi"
-Invoke-Installer msiexec.exe @('/i', $rustMsi, 'INSTALLDIR=C:\Rust', 'ADDLOCAL=Rustc,Cargo,Std', '/quiet', '/norestart')
-- 
gitgitgadget