fix: packages/playground/Dockerfile to reduce vulnerabilities (#4412)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE322-PCRE2-13637025

Co-authored-by: snyk-bot <snyk-bot@snyk.io>

Author: AhmedHanafy725

packages/playground/Dockerfile

@@ -21,7 +21,7 @@ RUN yarn install
 RUN yarn lerna run build --no-private && yarn workspace @threefold/playground build
 
 # install nginx
-FROM nginx:1.29.2-alpine
+FROM nginx:1.29.3-alpine
 
 # serve the build files using nginx
 COPY --from=build /app/packages/playground/dist /usr/share/nginx/html