Update java11-vertx to use a shadow jar

[alexellis]

Signed-off-by: Alex Ellis (OpenFaaS Ltd) alexellis2@gmail.com

Description

Update java11-vertx to use a shadow jar

Motivation and Context

@koogordo suggested that using a shadow jar reduces the total size of functions using this template. Early testing showed up to 100MB in saving, and removed the zip/unzip stage from the build, making it quicker.

How Has This Been Tested?

Tested by running a docker build inside the template folder and running the container with docker, the code continued to work as expected.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] Version change (see: Impact to existing users)

Optimization, plus an upgrade to Gradle 7.3.3

Impact to existing users

The change in gradle version may mean changing "compile" to "implementation" within your gradle scripts.

[alexellis]

I've also shown this to @pmlopes, so will go ahead and merge the changes.

Paulo also mentioned that there is a base image that already contains OpenJDK and Gradle on the Docker Hub, it could make builds quicker, the tradeoff is in the initial download time is slower.