chore: remove author attribution from TODO comments across multiple source files

Remove "(bob)" author prefix from all TODO comments in benchmark/method_call.wren, include/wren.h, src/main.c, src/wren_common.h, src/wren_compiler.c, src/wren_core.c, src/wren_value.c, src/wren_value.h, and src/wren_vm.c. Update the TODO_PATTERN regex in metrics script to match the new format without author parentheses. Also refactor test file counting in metrics to use os.walk with fnmatch for recursive directory traversal instead of glob.iglob.

test/constructor/default.wren

@@ -7,5 +7,5 @@ var foo = Foo.new
 io.write(foo is Foo) // expect: true
 io.write(foo.toString) // expect: Foo
 
-// TODO(bob): Test that class doesn't get default constructor if it has an
-// explicit one.
+// TODO: Test that class doesn't get default constructor if it has an explicit
+// one.

test/constructor/new.wren

@@ -1,5 +1,5 @@
 class Foo {
-  // TODO(bob): Do we want to require an explicit "new" here?
+  // TODO: Do we want to require an explicit "new" here?
   this new { io.write("zero") }
   this new(a) { io.write(a) }
   this new(a, b) { io.write(a + b) }