Build/Test Tools: Temporarily allow the NPM testing workflow to fail.

This changes the Test NPM GitHub Action workflow to temporarily allow the job validating build tools on Windows to fail.

When the `build:dev` Grunt task is run on Windows, the resulting hashes calculated by Webpack are different than other platforms. This seems to be related to how the `remove-accents` dependency is read and processed during the build script.

Since a Windows machine is not used to build WordPress on the build server, this will only affect local development installs for Windows contributors. While this is investigated, this workflow job can be allowed to fail.

Props bernhard-reiter, desrosj, Clorith, gziolo.
See #56615.

git-svn-id: https://develop.svn.wordpress.org/trunk@54277 602fd350-edb4-49c9-b593-d223f7449a82

Author: desrosj

.github/workflows/test-npm.yml

@@ -55,6 +55,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 20
     if: ${{ github.repository == 'WordPress/wordpress-develop' || github.event_name == 'pull_request' }}
+    continue-on-error: ${{ matrix.os == 'windows-latest' }}
     strategy:
       fail-fast: false
       matrix: