[BOARD] Add ISNO Super build environment (ESP32-S3, dual CC1101 433 + 868/915 MHz) (#2378)

The ISNO Super is an open-hardware ESP32-S3 board carrying two CC1101
sub-GHz radios (433 MHz and 868/915 MHz) combined on a single antenna
through a passive LC diplexer. This environment builds on the
esp32dev-multi_receiver RF stack; it drives the 868/915 MHz radio (868
in the EU, 915 in the US) and parks the 433 MHz one using the existing
RF_MODULE_SECONDARY_CS hook in commonRF.cpp.

Signed-off-by: Olivier Delafosse <olshad@gmail.com>

.github/workflows/environments.json

@@ -5,6 +5,7 @@
     "lastUpdated": "2025-12-24",
     "environments": {
         "all": [
+            "isno-super",
             "rfbridge",
             "rfbridge-direct",
             "theengs-bridge",