Test npm publish (#3554)

## About the changes

https://github.blog/changelog/2022-10-24-npm-v9-0-0-released/ introduced
a breaking change in the way they handle files inside package.json which
caused some issues with the way we pack and distribute Unleash:

> npm pack now follows a strict order of operations when applying ignore
rules. If a files array is present in the package.json, then rules in
.gitignore and .npmignore files from the root will be ignored.

What we discovered is that when having a nested .gitignore (the one we
have inside frontend), `npm publish` was taking that nested .gitignore
into account (despite the fact that we also have a package.json with
files inside the same folder). We tricked this by removing the `build`
folder from `frontend/.gitignore` and instead adding it into the root
`.gitignore` which is being ignored by `npm publish` following what's
stated in the release note above.

-----------------

Co-authored-by: Gard Rimestad <gard@getunleash.io>

.github/workflows/release.yaml

@@ -24,9 +24,6 @@ jobs:
         run: |
           yarn install --frozen-lockfile
           yarn --cwd ./frontend install --frozen-lockfile
-          ls -l ./frontend
-          ls -l ./frontend/build
-          npm publish --dry-run
       - name: Publish to npm
         run: |
           LATEST=$(npm show unleash-server version)

.gitignore

@@ -50,7 +50,8 @@ package-lock.json
 /website/i18n/*
 .env
 
-#report.json
+# Ignore frontend build
+frontend/build
 
 # Generated docs
 website/docs/reference/api/**/sidebar.js

frontend/.gitignore

@@ -41,7 +41,6 @@ typings/
 
 # Built
 dist
-build
 
 # IDE
 .idea/

frontend/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "files": [
     "index.js",
-    "build/"
+    "build"
   ],
   "engines": {
     "node": ">=18"

package.json

@@ -12,6 +12,7 @@
     "dist",
     "docs",
     "frontend/build",
+    "frontend/build/*",
     "frontend/index.js",
     "frontend/package.json"
   ],