Replace grpcio-tools version pin with range from nanopb (#55)

grpcio-tools is pinned to >=1.43 in nanopb (where it's consumed), so match this behavior.

This was previously causing grpcio-tools to be downloaded upon every firmware build when the grpcio-tools version is not latest.

Author: vidplace7

requirements.txt

@@ -1,5 +1,7 @@
 platformio==6.1.19
 nanopb==0.4.9.1
-grpcio-tools==1.82.1
 adafruit-nrfutil==0.5.3.post16
 meshtastic==2.7.11
+# Match grpcio-tools version pinning from nanopb (where it's consumed)
+# but cap it below 2.x so a major release can't break the build unannounced.
+grpcio-tools>=1.43.0,<2