Reduce Docker Daemon Context

### Subject of the issue

The context sends too much information, IMO

```
=> [internal] load build context 0.4s
=> => transferring context: 24.65MB
```

### Steps to reproduce
```
./gradlew clean build
docker build --no-cache -t img .
```
### Expected behaviour

The context can be reduced to only include the necessary files.

Ideally, multi-stage builds are used from a gradle base image, then copied to the JRE image.

Run ./gradlew clean build and docker build --no-cache -t img . to confirm the 24.65MB context. Inspect the Docker build inputs and the Gradle build setup, then compare the current image process with the requested multi-stage Gradle-to-JRE approach. Done means the build still succeeds while sending only necessary files and producing the intended JRE image.

Written by the indexing model from the issue text.