Bug 1799057 - Enable rust 1.57 features of the fallible_collections crate. r=RyanVM

To work around issues the older code has with 1.65.

Differential Revision: https://phabricator.services.mozilla.com/D161234

Cargo.lock

@@ -2155,6 +2155,7 @@ dependencies = [
  "detect_win32k_conflicts",
  "dom",
  "encoding_glue",
+ "fallible_collections",
  "fluent",
  "fluent-fallback",
  "fluent-ffi",

toolkit/library/rust/shared/Cargo.toml

@@ -104,6 +104,10 @@ url = "=2.1.0"
 # Force mio to stay at 0.8.0 to avoid windows-sys dependencies.
 mio = "=0.8.0"
 
+# Since we're building with at least rustc 1.63, enable rust 1.57 features.
+# This happens to work around issues the older code has with 1.65.
+fallible_collections = { version = "0.4", features = ["rust_1_57"] }
+
 [target.'cfg(not(target_os = "android"))'.dependencies]
 viaduct = "0.1"
 webext_storage_bridge = { path = "../../../components/extensions/storage/webext_storage_bridge" }