Update ubuntu Docker tag to v26

| datasource | package | from  | to       |
| ---------- | ------- | ----- | -------- |
| docker     | ubuntu  | 24.04 | resolute |

Author: renovate[bot]

Dockerfile

@@ -2,7 +2,7 @@
 
 FROM composer:2.9.2 AS composer-base-image
 FROM node:26.1.0 AS npm-base-image
-FROM ubuntu:24.04 AS ubuntu-base-image
+FROM ubuntu:26.04 AS ubuntu-base-image
 
 FROM npm-base-image AS npm-dependencies