Pre Release v2.0.0-beta.1

ci: make the emulator test work on GitHub runners

Start QEMU with the timer-group watchdogs disabled, as ESP-IDF's own QEMU runner does: on a slow
host they reset or crash the emulated chip during boot, which kept the CI runner's board in a
reset loop (and caused the "cache error" crash on every second boot locally). Boot waits are
longer, and on a failure the test prints the device's serial output and CI keeps it as the
emulator-serial-log artifact.