Gate raspi-config calls behind Shell.run_raspi_config() (fixes #321)

[makermelissa-piclaw]

Summary

The Python installer scripts in this repo shell out to raspi-config nonint ... to toggle SPI/I2C, set overscan, change boot behaviour, configure the fan service, etc. raspi-config is only shipped (and only honored) on Raspberry Pi OS — on DietPi, Ubuntu, and other Debian-based distros the binary is absent and shell.run_command returns falsy on the missing executable, so the tweak silently doesn't happen and the user sees a confusing command not found line mid-install. That's the underlying "non-Pi-OS distro" gap behind #321; the reporter's specific is_wayland()/loginctl complaint was already fixed when that helper was deleted in d14339d, but the broader raspi-config-unavailable problem on the same distro remained.

Approach

adafruit/Adafruit_Python_Shell#38 (now merged + released) added a reusable Shell.run_raspi_config(args, suppress_message=False, return_output=False, run_as_user=None) that gates on is_raspberry_pi_os() and short-circuits to a no-op on non-Pi-OS hosts (returning True, or "" when return_output=True so .strip() callers stay happy).

This PR migrates every raspi-config nonint call site in the repo's Python installers to use it.

File	Sites	What they toggle
adafruit-pitft.py	6	do_boot_behaviour, do_boot_splash, do_boot_target, do_overscan ×2
raspi-blinka.py	7	do_i2c, do_spi, do_serial_hw, do_serial, do_ssh, do_camera, disable_raspi_config_at_boot
raspi-spi-reassign.py	3	do_spi ×2 + get_spi (uses return_output=True + .strip())
joy-bonnet.py	2	do_i2c, do_overscan
retrogame.py	1	do_i2c
pitft-fbcp.py	1	do_spi
rtc.py	1	do_i2c
adafruit_fanservice.py	1	do_fan — was previously gated only on is_raspberry_pi(), which is true on DietPi-on-Pi-hardware

Total: 22 call sites across 8 files, +22 / −22 net.

The leading sudo on the old run_command lines is dropped: all of these installers already require root (require_root() or equivalent), so the inner sudo was redundant.

Out of scope

Bash-only scripts in this repo (pi-eyes.sh, arcade-bonnet.sh, rgb-matrix.sh, retrogame.sh, spectro.sh) still call raspi-config directly. They don't use adafruit_shell and would need a different fix; happy to follow up separately if you want that too.

Test plan

• Syntax (ast.parse) clean across all 8 files (pre-existing SyntaxWarnings on invalid escape sequences are unrelated).
• Confirmed via ast walk that all 22 migrated call sites resolve to syntactically valid shell.run_raspi_config(...) invocations, with suppress_message / return_output kwargs preserved on the three sites that use them.
• On this Pi (Raspberry Pi OS), with Shell.run_command monkey-patched to record calls: run_raspi_config("do_overscan 1") forwards to run_command("raspi-config nonint do_overscan 1", ...) exactly as before.
• On simulated non-Pi-OS (is_raspberry_pi_os patched to False): all calls short-circuit, return truthy / empty string, zero run_command invocations.

References

• Closes adafuit-pitft.py fails when using Dietpi linux distro #321.
• Depends on Add Shell.run_raspi_config() that no-ops on non-Raspberry-Pi-OS Adafruit_Python_Shell#38 (merged + released).

[makermelissa-piclaw]

Follow-up: I've also opened adafruit/Adafruit_Python_Shell#38 which adds the same gating logic as a reusable Shell.run_raspi_config() method, plus migrates the existing Shell.set_window_manager() call internally.

Once that lands and is released to PyPI, the local run_raspi_config() helper in this PR can be deleted in favor of shell.run_raspi_config(...), and the same migration can be applied to the other call sites in this repo (raspi-blinka.py, raspi-spi-reassign.py, joy-bonnet.py, retrogame.py, pitft-fbcp.py) — they all currently shell out to raspi-config nonint ... the same way.

Happy to do this either way:

• Land this PR as-is (self-contained local helper, ships immediately), then do a follow-up PR after the Shell release to migrate all six scripts to the library helper.
• Hold this PR until Shell add some hacky file copies for libgpiod python bindings #38 ships, then rewrite to depend on the new method directly.

Let me know which you'd prefer.

[makermelissa]

Looks good to me.