test: use symlinks to copy shells

Git for Windows includes `C:\Program Files\Git\bin\bash.exe`,
which spawns ..\usr\bin\bash.exe, so copying that executable
won't work.

However, if a symlink is used to test paths with spaces,
this executable will still work.

PR-URL: #32129
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

Author: John Kleinschmidt

test/parallel/test-child-process-exec-any-shells-windows.js

@@ -23,10 +23,10 @@ const test = (shell) => {
           }));
 };
 const testCopy = (shellName, shellPath) => {
-  // Copy the executable to a path with spaces, to ensure there are no issues
+  // Symlink the executable to a path with spaces, to ensure there are no issues
   // related to quoting of argv0
   const copyPath = `${tmpPath}\\${shellName}`;
-  fs.copyFileSync(shellPath, copyPath);
+  fs.symlinkSync(shellPath, copyPath);
   test(copyPath);
 };