chore: add jenkins validation pipeline

.jenkins/build-symfony-image.groovy

@@ -0,0 +1,15 @@
+def exec() {
+    String dockerfile = readFile(file:'Dockerfile')
+
+    dockerfile = """
+    ${dockerfile}
+
+    RUN apt update && apt install -y php-gd php-curl php-zip curl
+    RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash - && apt-get install -y nodejs
+    RUN npm install -g yarn
+    """.stripIndent()
+
+    writeFile(file:'Dockerfile', text: dockerfile)
+}
+
+return this

Jenkinsfile

@@ -0,0 +1,3 @@
+@Library('cadoles') _
+
+symfonyAppPipeline('ubuntu:22.04')