Outdated avr-gcc dependency

[kopsis]

package_aloriumtech_index.json is specifying an old avr-gcc package version (4.8.1-arduino5) that works in the Arduino IDE but is incompatible with the arduino-cli tools. Arduino's current package_index.json is specifying version 7.3.0-atmel3.6.1-arduino7 for Arduino AVR Boards. Adding a 2.3.1 package spec to my local copy of package_aloriumtech_index.json that calls out that newer avr-gcc version in toolsDependencies lets me target Sno boards with the arduino-cli tools.

[jpecor]

Thanks David! We're looking at this to see what it would mean for us to update this.