chore(deps): update ubuntu docker tag to v26

.gitlab-ci.yml

@@ -1,4 +1,4 @@
-image: docker:latest
+image: "docker:latest"
 
 services:
   - "docker:dind"

Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:26.04
 LABEL maintainer="Julien Cabillot <dockerimages@cabillot.eu>"
 
 # hadolint ignore=DL3008,SC3009,SC2086

renovate.json

@@ -1,17 +0,0 @@
-{
-  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "gitlabci": {
-    "enabled": true
-  },
-  "regexManagers": [
-    {
-      "description": "Track SHA-pinned Gitea Actions (github-actions manager on Gitea platform cannot resolve SHA refs natively)",
-      "fileMatch": ["^\\.gitea/workflows/.*\\.ya?ml$"],
-      "matchStrings": [
-        "uses:\\s+(?<depName>[\\w.-]+\\/[\\w.-]+(?:\\/[\\w.-]+)?)@(?<currentDigest>[a-f0-9]{40})"
-      ],
-      "datasourceTemplate": "github-releases",
-      "versioningTemplate": "semver"
-    }
-  ]
-}