Bump bindgen to 0.72 to fix the Rust build with the current libclang.

bindgen 0.71 generates opaque (field-less) structs for sentrypeer_config
and sip_message_event when run against llvm/clang 20+, which makes the
Rust code fail to compile with "no field ... on type" errors. bindgen
0.72 parses the headers correctly again.

--- a/sentrypeer_rust/Cargo.toml
+++ b/sentrypeer_rust/Cargo.toml
@@ -47,7 +47,7 @@
 ]
 
 [build-dependencies]
-bindgen = "0.71.1"
+bindgen = "0.72"
 cbindgen = "0.28.0"
 
 [lib]
--- a/sentrypeer_rust/Cargo.lock
+++ b/sentrypeer_rust/Cargo.lock
@@ -184,9 +184,9 @@
 
 [[package]]
 name = "bindgen"
-version = "0.71.1"
+version = "0.72.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f58bf3d7db68cfbac37cfc485a8d711e87e064c3d0fe0435b92f7a407f9d6b3"
+checksum = "993776b509cfb49c750f11b8f07a46fa23e0a1386ffc01fb1e7d343efc387895"
 dependencies = [
  "bitflags",
  "cexpr",
@@ -1204,7 +1204,7 @@
 version = "1.0.0"
 dependencies = [
  "assert_cmd",
- "bindgen 0.71.1",
+ "bindgen 0.72.1",
  "cbindgen",
  "chrono",
  "clap",