build: fix v8_use_perfetto source scraping

Signed-off-by: Chengzhong Wu <cwu631@bloomberg.net>

Author: legendecas

tools/v8_gypfiles/v8.gyp

@@ -1740,10 +1740,10 @@
         }],
         ['v8_use_perfetto==1', {
           'sources!': [
-            '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_libplatform.*?v8_use_perfetto.*?sources -= ")',
+            '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_libplatform.*?v8_use_perfetto.*?sources \\-= ")',
           ],
           'sources': [
-            '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_libplatform.*?v8_use_perfetto.*?sources += ")',
+            '<!@pymod_do_main(GN-scraper "<(V8_ROOT)/BUILD.gn"  "\\"v8_libplatform.*?v8_use_perfetto.*?sources \\+= ")',
           ],
           'dependencies': [
             '<(perfetto_gyp_file):perfetto_sdk',