clang-tidy: Drop unknown gcc compiler args

clang-tidy recently gained support to allow dropping
compiler args from the entries parsed from the compilation
database. Let's make use of this to drop the two compiler
args we use with gcc that clang doesn't support so we can
run clang-tidy on meson build trees configured to use gcc
without getting tons of false positives.

.clang-tidy

@@ -70,6 +70,7 @@ CheckOptions:
     ^getmntent$,mnt_table_next_fs(),libmount parser should be used instead
 '
   misc-header-include-cycle.IgnoredFilesList: 'glib-2.0'
+RemovedArgs: ['-fwide-exec-charset=UCS2', '-maccumulate-outgoing-args']
 WarningsAsErrors: '*'
 ExcludeHeaderFilterRegex: 'blkid\.h|gmessages\.h|gstring\.h'
 HeaderFileExtensions: