fix(onnxruntime): update to v1.21.1 to fix Eigen hash mismatch

ONNX Runtime v1.20.0 build fails due to hash mismatch when downloading
the Eigen dependency. Update to v1.21.1 which should have updated
dependency hashes.

Error:
  Hash of downloaded file has unexpected value
  expected: 'be8be39fdbc6e60e94fa7870b280707069b5b81a'
  actual: '32b145f525a8308d7ab1c09388b2e288312d8eba'

Author: jdalton

packages/onnxruntime/README.md

@@ -45,4 +45,4 @@ The CLI's `extract-onnx-runtime.mjs` script:
 
 ## Version
 
-Based on ONNX Runtime v1.20.0 (or latest stable).
+Based on ONNX Runtime v1.21.1.

packages/onnxruntime/scripts/build.mjs

@@ -54,7 +54,7 @@ const CLEAN_BUILD = args.includes('--clean')
 const ROOT_DIR = path.join(__dirname, '..')
 const BUILD_DIR = path.join(ROOT_DIR, 'build')
 const OUTPUT_DIR = path.join(BUILD_DIR, 'wasm')
-const ONNX_VERSION = 'v1.20.0'
+const ONNX_VERSION = 'v1.21.1'
 const ONNX_REPO = 'https://github.com/microsoft/onnxruntime.git'
 const ONNX_SOURCE_DIR = path.join(BUILD_DIR, 'onnxruntime-source')