Only test wasmtime-py and wasmtime-rust if nightly is installed. (#293)

* Only test wasmtime-py and wasmtime-rust if nightly is installed.

* Update test-all.sh

Co-Authored-By: bjorn3 <bjorn3@users.noreply.github.com>

test-all.sh

@@ -62,10 +62,6 @@ RUST_BACKTRACE=1 cargo test \
   --package wasmtime-interface-types \
   --package wasmtime-obj \
 
-RUST_BACKTRACE=1 cargo +nightly test \
-  --package wasmtime-py \
-  --package wasmtime-rust
-
 # Make sure the documentation builds.
 banner "Rust documentation: $topdir/target/doc/wasmtime/index.html"
 cargo doc
@@ -89,6 +85,11 @@ if rustup toolchain list | grep -q nightly; then
     # Nightly is available, so also run lightbeam's tests, which we
     # skipped earlier.
     cargo +nightly test --package lightbeam
+
+    # Also run wasmtime-py and wasmtime-rust's tests.
+    RUST_BACKTRACE=1 cargo +nightly test \
+      --package wasmtime-py \
+      --package wasmtime-rust
 else
     echo "nightly toolchain not found, skipping fuzz target integration test"
 fi