chore(release): bump build number to 464 for the v4.5.7 rebuild

Version name stays 4.5.7 so the release is overwritten in place; the build
number must increase for Android to accept the update. This rebuild carries
the upstream rt-bishop merge (18 commits) on top of the 30 audit fixes.

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 #noinspection UnusedVersionCatalogEntry
-appVersionCode = "463"
+appVersionCode = "464"
 #noinspection UnusedVersionCatalogEntry
 appVersionName = "4.5.7"
 #noinspection UnusedVersionCatalogEntry