intel-oneapi: fix parallel installer errors (#24911)

Intel oneAPI installs maintain a lock file in XDG_RUNTIME_DIR,
which by default exists in /tmp (and is shared by all component
installs). This prevented multiple oneAPI components from being
installed in parallel. This commit sets XDG_RUNTIME_DIR to exist
within Spack's installation Stage, so allows multiple components
to be installed at the same time.

lib/spack/spack/build_systems/oneapi.py

@@ -69,6 +69,9 @@ def install(self, spec, prefix, installer_path=None):
 
             # Installer writes files in ~/intel set HOME so it goes to prefix
             bash.add_default_env('HOME', prefix)
+            # Installer checks $XDG_RUNTIME_DIR/.bootstrapper_lock_file as well
+            bash.add_default_env('XDG_RUNTIME_DIR',
+                                 join_path(self.stage.path, 'runtime'))
 
             bash(installer_path,
                  '-s', '-a', '-s', '--action', 'install',