homebrew install - MAVEN_ARGS does not work

### Affected version

1.0.3

### Bug description

(yes, I am aware of #1219 and #1269)

In the Jdbi build, we heavily depend on setting MAVEN_ARGS to control build behavior. When replacing 'mvn' with 'mvnd', the values from the environment variable are not read.

- check out https://github.com/jdbi/jdbi (wait until https://github.com/jdbi/jdbi/pull/2889 was merged or patch the Makefile to read `MAVEN ?= ./mvnw`)
- run `MAVEN='./mvnw' make install-fast`. The build skips tests, checkers etc and builds the code
- run `MAVEN='mvnd' make install-fast`. The build will execute tests, checkers etc. because mvnd did not pick up `MAVEN_ARGS='-Pfast'` which is set in the Makefile

This is on macOS 15.7.1, Java 25, gnumake 3.81 (shipped with OS), mvnd 1.0.3 (installed from homebrew)

Reproduce the issue with the Jdbi Makefile's install-fast target, comparing MAVEN='./mvnw' and MAVEN='mvnd' while MAVEN_ARGS='-Pfast' is set. Start by tracing how mvnd reads environment arguments; done means mvnd honors MAVEN_ARGS and the mvnd build matches the fast Maven wrapper behavior.

Written by the indexing model from the issue text.