Revert "[nrf noup] test-spec: include nrf54 boards in low-level test trigger"

This reverts commit e7aa700.

Signed-off-by: Thomas Stilwell <[email protected]>

Author: thst-nordic

.github/test-spec.yml

@@ -293,7 +293,6 @@
 
 "CI-test-low-level":
   - "dts/**/*"
-  - "boards/nordic/nrf54*/**/*"
   - "include/zephyr/**/*"
   - "tests/arch/**/*"
   - "arch/**/*"