[Keymap] Drashna updates for 0.19 (#19175)

* Fix up bastardkb boards since blackpill support is officially added.
  * Check for blackpill version, not elite c.
  * Add checks in chibiOS config since multiple ARM controllers supported.
  * Rework rules.mk for keymaps to better handle arm vs avr support
* Start moving away from `matrix_*_*` functions.
  * `housekeeping_task_*` instead of `matrix_scan_*`
  * `keyboard_(pre|post)_init_*` instead of `matrix_init_*` 
* Add ℂℴmⅈℂ unicode input method.
* Clean up unicode code to be more compact and flexible.
* Remove/move Pro Micro LED commands to userspace and better filter them
* Fixup OLED code
  * Use newer quantum keycode functions/preprocessors rather than manual bit manipulation
  * Make unicode mode render much more compact/simple.
* Make qmk secrets more self contained
* Remove custom implementation of split watchdog

1 files changed, 0 insertions, 5 deletions

diff --git a/users/drashna/callbacks.md b/users/drashna/callbacks.md
index a0f0d9fdae..5908a66142 100644
--- a/users/drashna/callbacks.md
+++ b/users/drashna/callbacks.md
@@ -15,11 +15,6 @@ My [Ergodox EZ Keymap](https://github.com/qmk/qmk_firmware/blob/master/layouts/c
 You can see a list of these files in [callbacks.c](callbacks.c), or a shortend list here 
 
 ```c
-__attribute__((weak)) void matrix_init_keymap(void) {}
-void                       matrix_init_user(void) {
-    matrix_init_keymap();
-}
-
 __attribute__((weak)) void keyboard_post_init_keymap(void) {}
 void                       keyboard_post_init_user(void) {
     keyboard_post_init_keymap();