chore: Pin the nightly version (#5)

Signed-off-by: Noah Knegt <git@noahknegt.com>
Co-authored-by: Noah Knegt <git@noahkengt.com>
Reviewed-on: #5

rust-toolchain.toml

@@ -1,5 +1,7 @@
 [toolchain]
-channel = "nightly"
+# The nightly version that was build on 24-07-2025 is the last known working version,
+# the c-int-width definition for rust targets has changed from a string to a u16
+channel = "nightly-2025-07-24"
 targets = [
     "x86_64-unknown-none"
 ]