Based on the console output you’ve provided, it appears that you do not have your project configured to build for the right target MCU.
Navigate to Project -> Properties -> C/C++ Build -> Settings -> Target
Verify that the ‘board’ setting matches the board or MCU device you’re using.
There should be a pre-configured “board” definition for the STM32F3 Discovery, but I can’t say for certain because I’ve never tried selecting it.
In any event, the debugger is refusing to start up because the “idcode” of your target MCU does not match what the debugger is expecting to see.