fix dropping of resource borrows in async-lifted exports

Previously, I had been using a global variable to track borrows which needed to
be dropped when returning from an export, which works fine for sync-lifted
exports but not so fine for async-lifted ones.  In the latter case, we would
incorrectly drop borrows from other concurrent calls.  Now I've eliminated the
global variable in favor of tracking the borrows on a per-call basis.

This also includes few minor chores:

- Switch CI to use final CPython 3.14.0 release
- Update Wasmtime to v39.0.0
- Update to newer wasm-tools commit

I had also intended to update to WASI-SDK 29, but it seems to have broken the
TCP example.  Will debug that later.

Signed-off-by: Joel Dice <[email protected]>

Author: dicej

.github/workflows/release.yaml

@@ -30,7 +30,7 @@ jobs:
 
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.14.0-rc.3"
+          python-version: "3.14.0"
 
       - name: Install latest Rust nightly toolchain
         uses: dtolnay/rust-toolchain@nightly
@@ -145,7 +145,7 @@ jobs:
 
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.14.0-rc.3"
+          python-version: "3.14.0"
 
       - name: Install latest Rust nightly toolchain
         uses: dtolnay/rust-toolchain@nightly

.github/workflows/test.yaml

@@ -28,7 +28,7 @@ jobs:
 
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.14.0-rc.3"
+          python-version: "3.14.0"
 
       - name: Install latest Rust nightly toolchain
         uses: dtolnay/rust-toolchain@nightly
@@ -138,7 +138,7 @@ jobs:
 
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.14.0-rc.3"
+          python-version: "3.14.0"
 
       - name: Test
         shell: bash