Development tools for Zephyr on STM32Workbench for Zephyr: VS Code extension to set up, build, flash and debug Zephyr applications on STM32.Devicetree manager: browse, edit and visualize Zephyr devicetree, STM32CubeMX-like for Zephyr.
The STM32 mcu has an internal pull-up on reset pin, so you just need to connect pin 15 of STLink (on the 20 pin connector) to the Reset input of mcu. Nothing else.
And remove your hard wired reset connection to VCC.