m65 -k does not ensure Hypervisor is writeable first

[gardners]

Test Environment (required)

• Tools Platform: All platforms
• Tools Version: All versions
• MEGA65 Platform: All platforms
• ROM Release: N/A
• Core Commit: N/A

Describe the bug
m65 -k HICKUP.M65 should replace the running HYPPO image with the file provided. It does not.

To Reproduce
Steps to reproduce the behavior:

1. m65 -k HICKUP.M65 with any valid HICKUP.M65 file, ideally one different to the running one, so that it is easy to spot the difference (e.g., change the VERSION banner message in the HYPPO build).
2. Hold CTRL and press RESET button on MEGA65 so that HYPPO boot messages stay on screen.
3. Observe that old HYPPO version is still running.

Expected behavior
The new HYPPO image from the HICKUP.M65 file should be running.

Screenshots
N/A

Additional context
N/A