Force valid ClangFormat BasedOnStyle configuration key value

In order to facilitate maintenance and development, the ClangFormat configuration file is standardized by running a
`clang-format --dump-config` command while configured according to the current configuration file, then updating the
file according to the dumped effective configuration.

The configuration file generated using ClangFormat 14.0.0 contains a `BasedOnStyle` key set to an empty string
(`BasedOnStyle: ''`), even when configured via the arbitrary `BasedOnStyle: LLVM` setting previously used by Arduino's
configuration.

Since Arduino's configuration sets all configuration keys, the `BasedOnStyle` key has no effect, and so this is likely
not an issue. However, it is concerning because an empty string is not documented as a supported value.

Out of an abundance of caution and to avoid confusion, the value of this key is reset to the documented valid value
`LLVM`.

Author: per1234

Taskfile.yml

@@ -248,6 +248,13 @@ tasks:
           --style=file:"{{.CLANG_FORMAT_CONFIGURATION_PATH}}" >> \
             "{{.TARGET_PATH}}"
 
+      - |
+        # Correct invalid `BasedOnStyle` key value
+        # The existing key is deleted before assigning it to a valid value in order to achieve consistent quoting style
+        # (updating the empty string value in place causes the assigned value to be wrapped in quotes)
+        yq --inplace 'del(.BasedOnStyle)' "{{.TARGET_PATH}}"
+        yq --inplace '.BasedOnStyle = "LLVM"' "{{.TARGET_PATH}}"
+
       - |
         # Fix the inconsistent key order
         yq --inplace 'sort_keys(.)' "{{.TARGET_PATH}}"

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

@@ -26,7 +26,7 @@ AlwaysBreakBeforeMultilineStrings: false
 AlwaysBreakTemplateDeclarations: No
 AttributeMacros:
   - __capability
-BasedOnStyle: ''
+BasedOnStyle: LLVM
 BinPackArguments: true
 BinPackParameters: true
 BitFieldColonSpacing: Both

other/clang-format-configuration/notes.md

@@ -14,7 +14,7 @@ It is not clear from the documentation, but this truly is an "allow" setting, ra
 
 This key is irrelevant because we define all configuration keys.
 
-Even though it is not one of the documented possible values, `clang-format --dump-config` outputs `BasedOnStyle: ''`, so we use that.
+Even though it is not one of the documented possible values, `clang-format --dump-config` outputs `BasedOnStyle: ''`.
 
 ## `BraceWrapping`