Update Wasmtime used in testing/fuzzing (#2629)

* Update Wasmtime used in testing/fuzzing

Additionally helps fix a fuzz issue in the `no_traps` fuzzer where
compact imports need to be disabled. With this update the various
features there are additionally updated.

* Update toolchains in CI

* Fix no-traps compile

Author: alexcrichton

.github/workflows/main.yml

@@ -117,7 +117,7 @@ jobs:
           - os: ubuntu-latest
             rust: beta
           - os: ubuntu-latest
-            rust: nightly-2026-01-20
+            rust: nightly-2026-08-31
           - os: macos-latest
             rust: stable
           - os: windows-latest
@@ -130,7 +130,7 @@ jobs:
           # this is the rust nightly that oss-fuzz currently uses so we don't
           # want this to break.
           - os: ubuntu-latest
-            rust: nightly-2025-07-16
+            rust: nightly-2026-07-09
           # test that if `RUST_BACKTRACE=1` is set in the environment that all
           # tests with blessed error messages still pass.
           - os: ubuntu-latest
@@ -244,7 +244,7 @@ jobs:
         submodules: true
     - uses: ./.github/actions/install-rust
       with:
-        toolchain: nightly-2026-08-10
+        toolchain: nightly-2026-08-31
     - run: cargo install cargo-fuzz
     - run: cargo fuzz build --dev -s none
     - run: cargo fuzz build --dev --features wasmtime -s none