Update default toolchain version to 5.10.0 (#476)

* Check 5.10 RC toolchain

* Update the default toolchain version to stable wasm-5.10.0-RELEASE

Author: kateinoigakukun

Sources/CartonHelpers/DefaultToolchain.swift

@@ -12,4 +12,4 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-public let defaultToolchainVersion = "wasm-5.9.2-RELEASE"
+public let defaultToolchainVersion = "wasm-5.10.0-RELEASE"