[upstream] electron/patches/squirrel.mac/fix_abort_installation_attempt_at_the_final_mile_if_the_app_is.patch
[upstream] electron/patches/squirrel.mac/fix_resolve_target_bundle_path_once_at_start_of_install.patch

The first patch closes a race between ShipIt launching and performing
the atomic rename by checking running applications immediately before
the move. The second resolves the target bundle URL once up front,
rejects requests whose path traverses symlinks, and threads the
canonical URL through the rest of the chain so every step operates on
the location validation saw.

Adapted: guard the running-app check with a nil bundleIdentifier check
(NSRunningApplication throws when passed nil; existing fixtures use
nil intentionally).

Adds specs for: install rejected when targetBundleURL is a symlink;
install aborted with SQRLInstallerErrorAppStillRunning while the
target app is running.

[upstream] electron/patches/squirrel.mac/feat_add_ability_to_prevent_version_downgrades.patch

When the running app's Info.plist sets ElectronSquirrelPreventDowngrades
to true, refuse to install update bundles whose CFBundleShortVersionString
is lower than the current version (or where either side is not a simple
A.B.C version).

Adds unit specs for +isVersionAllowedForUpdate:from:. The end-to-end
'should not update to lower version numbers' / 'not a valid version
string' cases require Info.plist mutation on the running host bundle
and are covered by Electron's integration suite.

[upstream] electron/patches/squirrel.mac/refactor_use_posix_spawn_instead_of_nstask_so_we_can_disclaim_the.patch
[upstream] electron/patches/squirrel.mac/fix_trigger_shipit_mach_service_after_smjobsubmit_to_unblock.patch
[upstream] electron/patches/squirrel.mac/chore_turn_off_launchapplicationaturl_deprecation_errors_in_squirrel.patch

- ShipIt-main.m: use posix_spawn with the responsibility-disclaim flag
  when re-spawning the post-install relauncher so a hot-swapped binary
  can't inherit the parent's TCC permissions
- SQRLShipItLauncher.m: after SMJobSubmit, send a one-shot Mach message
  to the registered service so launchd starts the job even when the
  user domain is in on-demand-only mode (pending OS update)
- ShipIt-main.m: pragma-suppress the launchApplicationAtURL deprecation
  (replacement is 10.15+; tracked at electron/electron#43168)

No new specs: launchd / TCC / mach-port behaviour isn't reachable in a
unit test. Existing remote-ShipIt SQRLInstallerSpec specs continue to
exercise the new spawn path.

[upstream] electron/patches/squirrel.mac/refactor_use_non-deprecated_nskeyedarchiver_apis.patch

unarchiveObjectWithData: -> initForReadingFromData:error: + decodeObjectForKey:
archivedDataWithRootObject: -> archivedDataWithRootObject:requiringSecureCoding:error:

Adds a spec asserting SQRLInstallerOwnedBundle round-trips through the
ownedBundle property accessor pair (which is what writes/reads the
CFPreferences blob between ShipIt invocations).

[upstream] electron/patches/squirrel.mac/fix_clean_up_orphaned_staged_updates_before_downloading_new_update.patch

When checkForUpdates is called while an update is already staged,
Squirrel created a new temporary directory for the download without
cleaning up the old one. Chain a pruneOrphanedUpdateDirectories step
before uniqueTemporaryDirectoryForUpdate that reads the current
ShipItState.plist, preserves the directory it references, and deletes
every other update.* directory — keeping the on-disk footprint bounded
while quitAndInstall remains safe to call.

Adds specs:
- removeUpdateDirectoriesInStorageURL:excludingURL: deletes all
  update.* dirs except the excluded one and leaves non-prefixed files
  alone
- end-to-end via TestApplication: 3 sequential checks leave at most 2
  update directories on disk

Replaces the previously-xit'd 'should remove downloaded archives after
updating' (asserted 0, never matched the 7dffc4b semantics).