chore: Add NEXT_PUBLIC_INTERCOM_APP_ID to Dockerfile (#3330)

The Dockerfile has been updated to include the
`NEXT_PUBLIC_INTERCOM_APP_ID` environment variable. This change ensures
that the Intercom app ID is properly configured in the frontend
application.

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

frontend/Dockerfile

@@ -35,7 +35,7 @@ ARG NEXT_PUBLIC_PROJECT_NAME
 ARG NEXT_PUBLIC_POSTHOG_KEY
 ARG NEXT_PUBLIC_POSTHOG_HOST
 ARG SENTRY_AUTH_TOKEN
-
+ARG NEXT_PUBLIC_INTERCOM_APP_ID
 ENV NEXT_PUBLIC_ENV=$NEXT_PUBLIC_ENV
 ENV NEXT_PUBLIC_BACKEND_URL=$NEXT_PUBLIC_BACKEND_URL
 ENV NEXT_PUBLIC_SUPABASE_URL=$NEXT_PUBLIC_SUPABASE_URL
@@ -48,6 +48,7 @@ ENV NEXT_PUBLIC_PROJECT_NAME=$NEXT_PUBLIC_PROJECT_NAME
 ENV NEXT_PUBLIC_POSTHOG_KEY=$NEXT_PUBLIC_POSTHOG_KEY
 ENV NEXT_PUBLIC_POSTHOG_HOST=$NEXT_PUBLIC_POSTHOG_HOST
 ENV SENTRY_AUTH_TOKEN=$SENTRY_AUTH_TOKEN
+ENV NEXT_PUBLIC_INTERCOM_APP_ID=$NEXT_PUBLIC_INTERCOM_APP_ID
 
 # Next.js collects completely anonymous telemetry data about general usage.
 # Learn more here: https://nextjs.org/telemetry
@@ -101,6 +102,8 @@ ARG NEXT_PUBLIC_POSTHOG_HOST
 ENV NEXT_PUBLIC_POSTHOG_HOST=$NEXT_PUBLIC_POSTHOG_HOST
 ARG SENTRY_AUTH_TOKEN
 ENV SENTRY_AUTH_TOKEN=$SENTRY_AUTH_TOKEN
+ARG NEXT_PUBLIC_INTERCOM_APP_ID
+ENV NEXT_PUBLIC_INTERCOM_APP_ID=$NEXT_PUBLIC_INTERCOM_APP_ID
 
 # server.js is created by next build from the standalone output
 # https://nextjs.org/docs/pages/api-reference/next-config-js/output