Do not update toolchain - subject to breakage (rust-lang/rustup#3025)

Author: simbleau

.github/workflows/build.yml

@@ -27,8 +27,6 @@ jobs:
       - name: Pull Cargo dependencies
         if: steps.cache-cargo.outputs.cache-hit != 'true'
         run: |
-          rustup update $TOOLCHAIN
-          rustup default $TOOLCHAIN
           cargo install trunk
 
       # Build cache

rust-toolchain.toml

@@ -1,5 +1,5 @@
 # My server runs linux. For compatability, check
 # https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu.html
 [toolchain]
-channel = "nightly-2022-07-15"
+channel = "nightly"
 targets = [ "wasm32-unknown-unknown" ]