Merge pull request #327590 from Smaug123/fetchdeps-escaping

dotnet: fix fetchDeps null handling

pkgs/build-support/dotnet/build-dotnet-module/default.nix

···
         else
           ''$(mktemp -t "${pname}-deps-XXXXXX.nix")'';
       storeSrc = srcOnly args;
-      projectFileStr = lib.escapeShellArg projectFiles;
-      testProjectFileStr = lib.escapeShellArg testProjectFiles;
+      projectFileStr = lib.escapeShellArgs projectFiles;
+      testProjectFileStr = lib.escapeShellArgs testProjectFiles;
       path = lib.makeBinPath [
         coreutils
         runtimeShellPackage