fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE318-EXPAT-7908292
- https://snyk.io/vuln/SNYK-ALPINE318-EXPAT-7908293
- https://snyk.io/vuln/SNYK-ALPINE318-EXPAT-6241039
- https://snyk.io/vuln/SNYK-ALPINE318-EXPAT-6446356
- https://snyk.io/vuln/SNYK-ALPINE318-EXPAT-9459845

Author: snyk-bot

Dockerfile

@@ -1,4 +1,4 @@
-FROM nginx:1.25.3-alpine
+FROM nginx:1.26.3-alpine
 
 WORKDIR /var/www/codesandbox
 COPY www ./