Fix build

Follows the guidance give in the PR that breaks the build:
https://github.com/GitTools/build-images/pull/108/changes#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5R22-R26

Author: eddymoulton

.github/workflows/ci.yml

@@ -118,7 +118,7 @@ jobs:
         run: |
             git_command="git config --global --add safe.directory /app"
             test_command="dotnet test LibGit2Sharp.sln --configuration Release -p:TargetFrameworks=${{ matrix.tfm }} --logger "GitHubActions" -p:ExtraDefine=LEAKS_IDENTIFYING"
-            docker run -t --rm --platform linux/${{ matrix.arch }} -v "$PWD:/home/gittools/app" -w "/home/gittools/app" -e OPENSSL_ENABLE_SHA1_SIGNATURES=1 gittools/build-images:${{ matrix.distro }}-sdk-${{ matrix.sdk }} sh -c "$git_command && $test_command"
+            docker run -t --rm --platform linux/${{ matrix.arch }} --user "$(id -u):$(id -g)" -e HOME=/tmp -e DOTNET_CLI_HOME=/tmp -v "$PWD:/app" -w /app -e OPENSSL_ENABLE_SHA1_SIGNATURES=1 gittools/build-images:${{ matrix.distro }}-sdk-${{ matrix.sdk }} sh -c "$git_command && $test_command"
 
   nuget-push:
     name: Octopus NuGet Push