Add SpaceBeforeCaseColon key to ClangFormat configuration

The previous ClangFormat configuration was developed for use with ClangFormat 11.0.1. The version of ClangFormat now in
use by Arduino tools is 14.0.0.

This configuration key was added in the interim.

The key value set here was chosen in order to:

- Comply with the established Arduino code style

Author: per1234

other/clang-format-configuration/.clang-format

@@ -145,6 +145,7 @@ SpaceAfterLogicalNot: false
 SpaceAfterTemplateKeyword: false
 SpaceAroundPointerQualifiers: Default
 SpaceBeforeAssignmentOperators: true
+SpaceBeforeCaseColon: false
 SpaceBeforeCpp11BracedList: false
 SpaceBeforeCtorInitializerColon: true
 SpaceBeforeInheritanceColon: true