chore(deps): bump node in /reference-apps/typescript-api-first (#317)

Bumps node from 18-alpine to 26-alpine.

---
updated-dependencies:
- dependency-name: node
  dependency-version: 26-alpine
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

reference-apps/typescript-api-first/Dockerfile

@@ -1,5 +1,5 @@
 # Build stage
-FROM node:18-alpine AS builder
+FROM node:26-alpine AS builder
 
 WORKDIR /app
 
@@ -17,7 +17,7 @@ COPY src ./src
 RUN npm run build
 
 # Runtime stage
-FROM node:18-alpine
+FROM node:26-alpine
 
 WORKDIR /app