Update qmk and guix channels; adjust as necessary

* .envrc: Due to the update of the guix channel in channels.scm, CROSS_LIBRARY_PATH needs to
be set so avr-gcc can find avr-libc.
* channels.scm: Update guix channel.
* keyboards/keebio/levinson/keymaps/rekahsoft/keymap.c: Various updates following rebasing my
changes onto the tip of upstream qmk.
(#include): keymap_steno.h no longer needs to be explicitly included (there is a warning otherwise).
(_ADJUST): Lowered to 6 so that the sizeof my keymap is small, avoiding the check in
quantum/keymap_introspection.c:31 which results in a error "Number of keymap layers exceeds
maximum set by LAYER_STATE_(8|16|32)BIT". Its worth noting that this error can be overcome by
simply commenting out the check in quantum/keymap_introspection.c:31, however, adjusting this
is preferred.
(keymaps): RESET keycode is no longer available. QK_REBOOT effectively replaces it.

.envrc

@@ -1,10 +1,16 @@
 use_guix-shell() {
   CHANNEL_FILE=channels.scm
   if [ -f $CHANNEL_FILE ]; then
+    eval "$(guix time-machine -C $CHANNEL_FILE -- shell "$@" -- bash -c 'echo export GUIX_ENVIRONMENT=${GUIX_ENVIRONMENT}')"
     eval "$(guix time-machine -C $CHANNEL_FILE -- shell "$@" --search-paths)"
   else
+    eval "$(guix shell "$@" -- bash -c 'echo export GUIX_ENVIRONMENT=${GUIX_ENVIRONMENT}')"
     eval "$(guix shell "$@" --search-paths)"
   fi
 }
 
-use guix-shell avr-toolchain avrdude make python-wrapper
+use guix-shell gcc-cross-avr-toolchain avrdude make python-wrapper qmk git coreutils sed grep bash gawk diffutils
+
+# TODO: currently the following needs to be set to allow the linker to find avr-libc
+# See: https://issues.guix.gnu.org/69394
+export CROSS_LIBRARY_PATH=$GUIX_ENVIRONMENT/avr/lib/

channels.scm

@@ -1,11 +1,11 @@
 (list (channel
-       (name 'guix)
-       (url "https://git.savannah.gnu.org/git/guix.git")
-       (branch "master")
-       (commit
-        "273709932fa47f6ae56c96564a9415fdbff4a169")
-       (introduction
-        (make-channel-introduction
-         "9edb3f66fd807b096b48283debdcddccfea34bad"
-         (openpgp-fingerprint
-          "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))
+        (name 'guix)
+        (url "https://git.savannah.gnu.org/git/guix.git")
+        (branch "master")
+        (commit
+          "2394a7f5fbf60dd6adc0a870366adb57166b6d8b")
+        (introduction
+          (make-channel-introduction
+            "9edb3f66fd807b096b48283debdcddccfea34bad"
+            (openpgp-fingerprint
+              "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))

keyboards/keebio/levinson/keymaps/rekahsoft/keymap.c

@@ -1,5 +1,4 @@
 #include QMK_KEYBOARD_H
-#include "keymap_steno.h"
 
 #define _QWERTY 0
 #define _COLEMAK 1
@@ -7,7 +6,7 @@
 #define _STENO 3
 #define _LOWER 4
 #define _RAISE 5
-#define _ADJUST 16
+#define _ADJUST 6
 
 enum custom_keycodes {
   QWERTY = SAFE_RANGE,
@@ -147,7 +146,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  * `-----------------------------------------------------------------------------------'
  */
 [_ADJUST] =  LAYOUT_ortho_4x12( \
-  _______, RESET,   _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_DEL, \
+  _______, QK_REBOOT, _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_DEL, \
   _______, _______, _______, AU_ON,   AU_OFF,  AG_NORM, AG_SWAP, QWERTY,  COLEMAK, DVORAK,  STENO,   _______, \
   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, \
   _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______ \