Why does Vaadin require a license in the Docker build? - vaadin

Question

I am using Vaadin 23.5.5 for a private project without using the Pro components of Vaadin. When I build the project in a Docker container, Vaadin aborts the build and asks for a license key file.
...
Running Vite ...
Opening the system browser to validate the license. If the browser is not open, please open https://vaadin.com/pro/validate-license?connect=UUID&productName=vaadin-board&productVersion=23.3.5 manually.
If you are working offline, please visit https://vaadin.com/pro/validate-license?getOfflineKey=ABC for an offline license.
...
This are my dependencies:
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-jersey'
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.springframework.boot:spring-boot-starter-webflux'
implementation 'com.google.cloud:spring-cloud-gcp-starter'
implementation 'com.google.cloud:spring-cloud-gcp-starter-storage'
implementation 'com.vaadin:vaadin-spring-boot-starter'
implementation 'org.springframework.boot:spring-boot-starter-security'
implementation 'com.google.cloud:spring-cloud-gcp-starter-data-firestore'
compileOnly 'org.projectlombok:lombok'
developmentOnly 'org.springframework.boot:spring-boot-devtools'
annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
annotationProcessor 'org.projectlombok:lombok'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
testImplementation 'io.projectreactor:reactor-test'
implementation 'de.jfancy:star-rating:1.0.3'
}
dependencyManagement {
imports {
mavenBom "com.vaadin:vaadin-bom:${vaadinVersion}"
mavenBom "com.google.cloud:spring-cloud-gcp-dependencies:${springCloudGcpVersion}"
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
}
}
The entire dependency tree:
https://gist.github.com/benocms/1d08207e5a89f6d50965a5136938a8a8
My understanding is that the use of the Core components is free. Am I wrong about this? Or is this a bug?