fix: remove wasm32v1-none target for serde_core + Rust 1.88 bug

WASM builds were failing with getrandom/serde_core error when using
wasm32v1-none target. By removing the 'rustup target add wasm32v1-none'
step, wasm-builder will automatically fallback to wasm32-unknown-unknown.

Jobs fixed:
- build-linux-stable
- build-linux-stable-pezcumulus
- build-test-teyrchain
- build-test-collators
- build-malus
- build-linux-bizinikiwi
- build-templates-node
- tests-evm differential and evm-tests
- test-node-metrics

Tracking: https://github.com/pezkuwichain/pezkuwi-sdk/issues/358

.github/workflows/tests-misc.yml

@@ -281,8 +281,8 @@ jobs:
           rm -rf ~/.cargo/registry/cache 2>/dev/null || true
           rm -rf ~/.cargo/git/db 2>/dev/null || true
 
-      - name: Add wasm32v1-none target
-        run: rustup target add wasm32v1-none
+      # NOTE: wasm32v1-none target removed - serde_core + Rust 1.88 bug
+      # wasm-builder will fallback to wasm32-unknown-unknown automatically
 
       - name: Run tests
         id: tests