[ci] Stop disabling SIMD tests under windows. NFC (#23539)

These only require node 16, and emsdk ships with node 20 these days.

See
https://chromium-review.googlesource.com/c/emscripten-releases/+/6216543

Author: sbc100

.circleci/config.yml

@@ -984,7 +984,6 @@ jobs:
       EMTEST_SKIP_V8: "1"
       EMTEST_SKIP_EH: "1"
       EMTEST_SKIP_WASM64: "1"
-      EMTEST_SKIP_SIMD: "1"
       EMTEST_SKIP_SCONS: "1"
       EMTEST_SKIP_RUST: "1"
       EMTEST_SKIP_NODE_CANARY: "1"