fix: test MSRV 1.70 in CI and ALSA stream shutdown race (#1076)

* fix: test MSRV 1.70 in CI and use AtomicBool in ALSA

* ci: use platform-specific MSRV in CI and docs
fix: bump WASM minimum Rust version to 1.77

* fix: set Android example to Rust 2021 edition

* ci: refactor workflows

* ci: pin iOS example build to aarch64 simulator

Author: roderickvd

.github/actions/setup-asio/action.yml

@@ -0,0 +1,14 @@
+name: Setup ASIO SDK
+description: Downloads and sets up the ASIO SDK for Windows builds
+
+runs:
+  using: composite
+  steps:
+    - name: Download and setup ASIO SDK
+      shell: pwsh
+      run: |
+        curl -L -o asio.zip https://www.steinberg.net/asiosdk
+        7z x -oasio asio.zip
+        move asio\*\* asio\
+        choco install asio4all
+        choco install llvm