Update .gitignore to new layout

.gitignore

@@ -2,16 +2,9 @@
 __pycache__/
 *.py[cod]
 
-# Ignore build directory
-/build
-
-# Ignore downloaded Chromium source archives
-/chromium-*.*.*.*.tar.xz
-/chromium-*.*.*.*.tar.xz.hashes
-
-# Ignore downloaded syzygy archive
-/syzygy-*.tar.gz
+# Ignore buildspace directory
+/buildspace
 
 # Ignore macOS Finder meta
 .DS_Store
-.tm_properties
+.tm_properties