Zephyr Workbench, a VSCode extension to manage Zephyr on STM32.
It enables users to easily create, develop, and debug Zephyr applications.
Main features:
Install host dependencies.
Import toolchain and SDK.
Create, configure, build and manage apps.
Debug STM32.
You can directly download it from the VSCode marketplace
For more details, visit the Zephyr Workbench
I managed to fix it now -> it was a hardware problem, my cheap StLink V2 mini clone seemed to have a broken connection to the RST ping. Using a different unit fixed the problem and I can use the stock configuration to flash my STM32.