Update rust in flake.nix: 1.70.0 -> 1.71.1 to address CVE-2023-38497 (#16260)

changelog.d/16260.misc

@@ -0,0 +1 @@
+Update rust to version 1.71.1 in the nix development environment.

flake.lock

@@ -258,11 +258,11 @@
         "nixpkgs": "nixpkgs_3"
       },
       "locked": {
-        "lastModified": 1690510705,
-        "narHash": "sha256-6mjs3Gl9/xrseFh9iNcNq1u5yJ/MIoAmjoaG7SXZDIE=",
+        "lastModified": 1693966243,
+        "narHash": "sha256-a2CA1aMIPE67JWSVIGoGtD3EGlFdK9+OlJQs0FOWCKY=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "851ae4c128905a62834d53ce7704ebc1ba481bea",
+        "rev": "a8b4bb4cbb744baaabc3e69099f352f99164e2c1",
         "type": "github"
       },
       "original": {

flake.nix

@@ -82,7 +82,7 @@
                   #
                   # NOTE: We currently need to set the Rust version unnecessarily high
                   # in order to work around https://github.com/matrix-org/synapse/issues/15939
-                  (rust-bin.stable."1.70.0".default.override {
+                  (rust-bin.stable."1.71.1".default.override {
                     # Additionally install the "rust-src" extension to allow diving into the
                     # Rust source code in an IDE (rust-analyzer will also make use of it).
                     extensions = [ "rust-src" ];