legacy sanitizing prefs

In FF128 these were used to migrate to
- clearOnShutdown to clearOnShutdown_v2
- cpd to clearHistory

They are then no longer used.

The migration can be checked with
- privacy.sanitize.clearOnShutdown.hasMigratedToNewPrefs2
- privacy.sanitize.cpd.hasMigratedToNewPrefs2

Note: in FF136 there was another migration, where it changes the `ToNewPrefs2` to false
- privacy.sanitize.clearOnShutdown.hasMigratedToNewPrefs3
- privacy.sanitize.cpd.hasMigratedToNewPrefs3

AFAICT, cpd.hasMigrated* doesn't migrate until you open the clear history dialog.

scratchpad-scripts/arkenfox-cleanup.js

@@ -6,7 +6,7 @@
   There is an archived version at https://github.com/arkenfox/user.js/issues/123
   if you want the full list since jesus
 
-  Last updated: 13-January-2025
+  Last updated: 5-March-2025
 
   Instructions:
   - [optional] close Firefox and backup your profile
@@ -76,6 +76,19 @@
     /* 129-140 */
     'dom.securecontext.allowlist_onions',
     'network.http.referer.hideOnionSource',
+    'privacy.clearOnShutdown.cache',
+    'privacy.clearOnShutdown.cookies',
+    'privacy.clearOnShutdown.downloads',
+    'privacy.clearOnShutdown.formdata',
+    'privacy.clearOnShutdown.history',
+    'privacy.clearOnShutdown.offlineApps',
+    'privacy.clearOnShutdown.sessions',
+    'privacy.cpd.cache',
+    'privacy.cpd.cookies',
+    'privacy.cpd.formdata',
+    'privacy.cpd.history',
+    'privacy.cpd.offlineApps',
+    'privacy.cpd.sessions',
     /* 116-128 */
     'browser.fixup.alternate.enabled',
     'browser.taskbar.previews.enable',