Update Rust to 1.76.0 (#6683)

[Release notes](https://github.com/rust-lang/rust/releases/tag/1.75.0).

Dockerfile.buildtools

@@ -135,7 +135,7 @@ WORKDIR /home/nonroot
 
 # Rust
 # Please keep the version of llvm (installed above) in sync with rust llvm (`rustc --version --verbose | grep LLVM`)
-ENV RUSTC_VERSION=1.75.0
+ENV RUSTC_VERSION=1.76.0
 ENV RUSTUP_HOME="/home/nonroot/.rustup"
 ENV PATH="/home/nonroot/.cargo/bin:${PATH}"
 RUN curl -sSO https://static.rust-lang.org/rustup/dist/$(uname -m)-unknown-linux-gnu/rustup-init && whoami && \

compute_tools/src/pg_helpers.rs

@@ -264,9 +264,10 @@ pub fn wait_for_postgres(pg: &mut Child, pgdata: &Path) -> Result<()> {
     // case we miss some events for some reason. Not strictly necessary, but
     // better safe than sorry.
     let (tx, rx) = std::sync::mpsc::channel();
-    let (mut watcher, rx): (Box<dyn Watcher>, _) = match notify::recommended_watcher(move |res| {
+    let watcher_res = notify::recommended_watcher(move |res| {
         let _ = tx.send(res);
-    }) {
+    });
+    let (mut watcher, rx): (Box<dyn Watcher>, _) = match watcher_res {
         Ok(watcher) => (Box::new(watcher), rx),
         Err(e) => {
             match e.kind {

control_plane/src/background_process.rs

@@ -72,7 +72,6 @@ where
     let log_path = datadir.join(format!("{process_name}.log"));
     let process_log_file = fs::OpenOptions::new()
         .create(true)
-        .write(true)
         .append(true)
         .open(&log_path)
         .with_context(|| {

rust-toolchain.toml

@@ -1,5 +1,5 @@
 [toolchain]
-channel = "1.75.0"
+channel = "1.76.0"
 profile = "default"
 # The default profile includes rustc, rust-std, cargo, rust-docs, rustfmt and clippy.
 # https://rust-lang.github.io/rustup/concepts/profiles.html