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/string/contains.wren

@@ -5,4 +5,4 @@ io.write("something".contains("some")) // expect: true
 io.write("something".contains("ing"))  // expect: true
 io.write("something".contains("math")) // expect: false
 
-// TODO(bob): Passing non-string as argument.
+// TODO: Passing non-string as argument.

test/string/escapes.wren

@@ -4,5 +4,5 @@ io.write("\\")     // expect: \
 io.write("(\n)")   // expect: (
                    // expect: )
 
-// TODO(bob): Non-printing escapes like \t.
-// TODO(bob): Unicode escape sequences.
+// TODO: Non-printing escapes like \t.
+// TODO: Unicode escape sequences.

test/string/subscript.wren

@@ -11,14 +11,14 @@ io.write("abcd"[-2]) // expect: c
 io.write("abcd"[-1]) // expect: d
 
 // Handle out of bounds.
-// TODO(bob): Should halt the fiber or raise an error somehow.
+// TODO: Should halt the fiber or raise an error somehow.
 io.write("abcd"[4])  // expect: null
 io.write("abcd"[-5]) // expect: null
 
 // Handle wrong argument type.
-// TODO(bob): Should halt the fiber or raise an error somehow.
+// TODO: Should halt the fiber or raise an error somehow.
 io.write("abcd"[true]) // expect: null
 
 // Handle non-integer index.
-// TODO(bob): Should halt the fiber or raise an error somehow.
+// TODO: Should halt the fiber or raise an error somehow.
 io.write("abcd"[1.5]) // expect: null