build: memoize npmVersion for devDependencies

The current iteration of the publish_packages script is very slow. The
main culprit is the `npm view` command, which is executed for each
internal dependency and devDependency of every standalone package. This
command is slow because it requires a network request to the npm
registry. This commit adds a memoization layer to the script, which
caches the results of the `npm view` command. In doing so, we have to
separate the memoization cache for dependencies and devDependencies
because the topological sort of the dependency graph is performed only
for production dependencies and thus a first call to `npm view` for a
devDependency is not guaranteed to reflect the latest version of the
dependency that was published to the npm registry during the current
execution of the script.

lib/node_modules/@stdlib/_tools/scripts/publish_packages.js

@@ -41,6 +41,7 @@ var readJSON = require( '@stdlib/fs/read-json' ).sync;
 var existsSync = require( '@stdlib/fs/exists' ).sync;
 var hasOwnProp = require( '@stdlib/assert/has-own-property' );
 var contains = require( '@stdlib/assert/contains' );
+var memoize = require( '@stdlib/utils/memoize' );
 var repeat = require( '@stdlib/string/repeat' );
 var trim = require( '@stdlib/string/trim' );
 var copy = require( '@stdlib/utils/copy' );
@@ -324,6 +325,8 @@ var BASIC_GITHUB_TOPICS = [
 	'node-js'
 ];
 var RE_ALLOWED_TOPIC_CHARS = /^[A-Z0-9-]+$/i;
+var memoizedNPMversionForDeps = memoize( npmVersion );
+var memoizedNPMversionForDevDeps = memoize( npmVersion );
 
 
 // FUNCTIONS //
@@ -387,7 +390,7 @@ function populateDeps( pkgJSON, deps, devDeps, mainJSON, useGitHub ) {
 				if ( useGitHub ) {
 					out.dependencies[ dep ] = 'github:stdlib-js/' + replace( dep, '@stdlib/', '' ) + '#main';
 				} else {
-					out.dependencies[ dep ] = npmVersion( dep );
+					out.dependencies[ dep ] = memoizedNPMversionForDeps( dep );
 				}
 			}
 		} else {
@@ -409,7 +412,7 @@ function populateDeps( pkgJSON, deps, devDeps, mainJSON, useGitHub ) {
 					if ( useGitHub ) {
 						out.devDependencies[ dep ] = 'github:stdlib-js/' + replace( dep, '@stdlib/', '' ) + '#main';
 					} else {
-						out.devDependencies[ dep ] = npmVersion( dep );
+						out.devDependencies[ dep ] = memoizedNPMversionForDevDeps( dep );
 					}
 				}
 			} else {