build(npmrc): Explicitly configure the Node version to use

While `package.json` files have `engines.node` set, that specifies a range
of compatible runtime Node versions, but not the exact version to build
the project.

Choose the current version from the 20 branch.

Signed-off-by: Sebastian Schuberth <sebastian@doubleopen.org>

src/.npmrc

@@ -1,4 +1,5 @@
 # pnpm-related options
 shamefully-hoist=true
 strict-peer-dependencies=false
-engine-strict = true
+engine-strict=true
+use-node-version=20.13.1