Upgrade clang-format version (#3471)

This apparently includes a fix for
https://github.com/llvm/llvm-project/issues/47664 (previously
https://bugs.llvm.org/show_bug.cgi?id=48320)

Note this continues with a clang-format version that's different from
the compiler versions we're often using, but the differences in
formatting seem worthwhile.

toolchain/check/handle_modifier.cpp

@@ -67,7 +67,7 @@ static auto HandleModifier(Context& context, Parse::NodeId parse_node,
 #define CARBON_PARSE_NODE_KIND(...)
 #define CARBON_PARSE_NODE_KIND_TOKEN_MODIFIER(Name, ...)                  \
   auto Handle##Name##Modifier(Context& context, Parse::NodeId parse_node) \
-      ->bool {                                                            \
+      -> bool {                                                           \
     return HandleModifier(context, parse_node, KeywordModifierSet::Name); \
   }
 #include "toolchain/parse/node_kind.def"