Bump MSRV to nightly 2022-09-04

This is required since adding the no-op personality function breaks older
versions of rust which have `eh_personality` in the `panic_unwind` crate.

README.md

@@ -56,7 +56,7 @@ implementations of graphics functions, and the addition of missing libraries.
 ## Dependencies
 
 To compile for the PSP, you will need a Rust **nightly** version equal to or
-later than `2022-06-11` and the `rust-src` component. Please install Rust using
+later than `2022-09-04` and the `rust-src` component. Please install Rust using
 https://rustup.rs/
 
 Use the following if you are new to Rust. (Feel free to set an override manually

cargo-psp/src/main.rs

@@ -120,13 +120,13 @@ impl fmt::Display for CommitDate {
     }
 }
 
-// Minimum 2022-06-11, remember to update both commit date and version too,
+// Minimum 2022-09-04, remember to update both commit date and version too,
 // below. Note that the `day` field lags by one day, as the toolchain always
 // contains the previous days' nightly rustc.
 const MINIMUM_COMMIT_DATE: CommitDate = CommitDate {
     year: 2022,
-    month: 06,
-    day: 10,
+    month: 09,
+    day: 04,
 };
 const MINIMUM_RUSTC_VERSION: Version = Version {
     major: 1,

ci/concourse/build-rust-macos.yml

@@ -1,7 +1,7 @@
 platform: darwin
 
 params:
-  RUSTUP_TOOLCHAIN: nightly-2022-06-11
+  RUSTUP_TOOLCHAIN: nightly-2022-09-04
 
 inputs:
   - name: repo

ci/concourse/build-rust.yml

@@ -11,7 +11,7 @@ image_resource:
     tag: 1.44-slim
 
 params:
-  RUSTUP_TOOLCHAIN: nightly-2022-06-11
+  RUSTUP_TOOLCHAIN: nightly-2022-09-04
 
 inputs:
   - name: repo