the latest npm doesn't support setting python as a config like `npm
config set python3` instead it needs to be either set in the node-gyp
explicitly using the node-gyp command or through an environment
variable.
Since we are calling the node-gyp through npm, we need to set the
environment variable which is documented here: https://github.com/nodejs/node-gyp?tab=readme-ov-file#configuring-python-dependency
Accordingly the CMakeLists.txt for dashboard is adapted
Fixes: https://tracker.ceph.com/issues/62844
Signed-off-by: Nizamudeen A <nia@redhat.com>