Expose `napi_build_version` to allow `node-gyp` to make it
available for building native addons.
Fixes: https://github.com/nodejs/node-gyp/issues/1745
Refs: https://github.com/nodejs/abi-stable-node/issues/371
PR-URL: https://github.com/nodejs/node/pull/27835
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
