Revert "Don't specify a patch version of rust in rust-toolchain"

This reverts commit 67eb290.

rust-toolchain

@@ -5,6 +5,6 @@
 # to the user in the error, instead of "error: invalid channel name '[toolchain]'".
 
 [toolchain]
-channel = "1.76"  # Avoid specifying a patch version here; see https://github.com/emilk/eframe_template/issues/145
+channel = "1.76.0"
 components = ["rustfmt", "clippy"]
 targets = ["wasm32-unknown-unknown"]