centraldashboard: Update node and use latest-stable (kubeflow#6260)

Change the tests to NOT fetch Chromium from the Edge branch, which is develop,
but instead use latest-stable. We saw that edge can have problems from times to
times.

In the same commit we also update the node version to fix CVEs with the current
v12.18.3 version that we had.

Signed-off-by: Kimonas Sotirchos <kimwnasptd@arrikto.com>

components/centraldashboard/Dockerfile

@@ -1,5 +1,5 @@
 # Step 1: Builds and tests
-FROM node:12.18.3-alpine AS build
+FROM node:12.22.8-alpine AS build
 
 ARG kubeflowversion
 ARG commit
@@ -8,19 +8,20 @@ ENV BUILD_COMMIT=$commit
 ENV CHROME_BIN=/usr/bin/chromium-browser
 ENV PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=true
 
-# Installs latest Chromium package and configures environment for testing
+# Installs latest-stable Chromium package and configures environment for testing
 RUN apk update && apk upgrade && \
-    echo @edge http://nl.alpinelinux.org/alpine/edge/community >> /etc/apk/repositories && \
-    echo @edge http://nl.alpinelinux.org/alpine/edge/main >> /etc/apk/repositories && \
-    apk add --no-cache bash chromium@edge nss@edge \
-    freetype@edge \
-    harfbuzz@edge \
-    ttf-freefont@edge \
-    libstdc++@edge
+    echo @stable http://nl.alpinelinux.org/alpine/latest-stable/community >> /etc/apk/repositories && \
+    echo @stable http://nl.alpinelinux.org/alpine/latest-stable/main >> /etc/apk/repositories
+
+RUN apk add --no-cache bash chromium@stable nss@stable \
+    freetype@stable \
+    harfbuzz@stable \
+    ttf-freefont@stable \
+    libstdc++@stable
 
 RUN if [ "$(uname -m)" = "aarch64" ]; then \
         apk update && apk upgrade && \
-        apk add --no-cache python2 make g++@edge; \
+        apk add --no-cache python2 make g++@stable; \
     fi
 
 COPY . /centraldashboard
@@ -39,7 +40,7 @@ RUN npm rebuild && \
     npm prune --production
 
 # Step 2: Packages assets for serving
-FROM node:12.18.3-alpine AS serve
+FROM node:12.22.8-alpine AS serve
 
 ENV NODE_ENV=production
 WORKDIR /app