[PATCH v2 2/4] ci(gitlab,windows): preserve exclusions during dependency setup

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

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

Creating .git/info/exclude as a file with `New-Item` and `-Force`
truncates existing contents.

When install-dependencies.ps1 follows install-sdk.ps1, this discards
the latter's /git-sdk exclusion and causes ci/lib.sh to reject SDK
files as unignored build artifacts.

Assisted-by: GPT-6
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 ci/install-dependencies.ps1 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ci/install-dependencies.ps1 b/ci/install-dependencies.ps1
index 8c68fb0cfc..f6868dc670 100755
--- a/ci/install-dependencies.ps1
+++ b/ci/install-dependencies.ps1
@@ -12,7 +12,9 @@ $RustVersion = '1.96.0'
 
 New-Item -Path $DownloadDirectory -ItemType Directory -Force | Out-Null
 New-Item -Path .git/info -ItemType Directory -Force | Out-Null
-New-Item -Path .git/info/exclude -ItemType File -Force | Out-Null
+if (-not (Test-Path .git/info/exclude)) {
+    New-Item -Path .git/info/exclude -ItemType File | Out-Null
+}
 Add-Content -Path .git/info/exclude -Value "/$DownloadDirectory"
 
 function Get-Installer {
-- 
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