Update repositories.txt

[axlan]

Added pixels-dice-interface library.

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/axlan/arduino-pixels-dice.git:

Linting library in arduino-pixels-dice
INFO: No header file found matching library name (pixels-dice-interface.h). Best practices are for primary header       
      filename to match library name.                                                                                   
      See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format            
      (Rule LS008)                                                                                                      
WARNING: library.properties name value pixels-dice-interface is longer than the recommended length of 16 characters.
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format     
         (Rule LP010)                                                                                               

Linter results for project: 0 ERRORS, 1 WARNINGS

-------------------

Linting sketch in arduino-pixels-dice/examples/Serial

Linter results for project: no errors or warnings

-------------------

Linting sketch in arduino-pixels-dice/examples/WebRequest

Linter results for project: no errors or warnings

-------------------

Linter results for projects: 0 ERRORS, 1 WARNINGS

[github-actions]

Your submission has now been accepted! Thanks for your contribution to the Arduino Library Manager index.

The library(s) will be available for installation via Library Manager within a day's time.

You can check the logs from the Library Manager indexer for your library(s) here:
http://downloads.arduino.cc/libraries/logs/github.com/axlan/arduino-pixels-dice/