Add ML-KEM with Curve25519 and NISTp384

1. Add GitHub action to test wolfSSL against OpenSSH using MLKEM.

Author: ejohnstown

.github/workflows/interop-mlkem.yml

@@ -0,0 +1,62 @@
+name: ML-KEM Interop Tests
+
+on:
+  push:
+    branches: [ 'draft-ietf-sshm-mlkem-hybrid-kex' ]
+  pull_request:
+    branches: [ '*' ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  wolfssl: v5.8.4-stable
+  os: ubuntu-latest
+  cache_key: wolfssh-mlkem-wolfssl-${{ env.wolfssl }}-${{ env.os }}
+
+jobs:
+  build_wolfssl:
+    name: Build wolfssl
+    runs-on: ${{ env.os }}
+    timeout-minutes: 4
+    steps:
+      - name: Checking cache for wolfSSL
+        uses: actions/cache@v4
+        id: cache-wolfssl
+        with:
+          path: build-dir/
+          key: ${{ env.cache_key }}
+          lookup-only: true
+
+      - name: Checkout, build, and install wolfSSL
+        if: steps.cache-wolfssl.outputs.cache-hit != 'true'
+        uses: wolfSSL/actions-build-autotools-project@v1
+        with:
+          repository: wolfSSL/wolfssl
+          ref: ${{ env.wolfssl }}
+          path: wolfssl
+          configure: --enable-wolfssh --enable-mlkem --enable-curve25519 --enable-base64encode --enable-cryptonly --disable-examples --disable-crypttests
+          check: false
+          install: true
+
+  build_wolfssh:
+    name: Build wolfssh
+    runs-on: ${{ env.os }}
+    timeout-minutes: 4
+    needs: [build_wolfssl]
+    steps:
+      - name: Checking cache for wolfSSL
+        uses: actions/cache@v4
+        with:
+          path: build-dir/
+          key: wolfssh-mlkem-wolfssl-${{ env.wolfssl }}-${{ env.os }}
+          fail-on-cache-miss: true
+
+      - name: Checkout, build, and test wolfSSH
+        uses: wolfSSL/actions-build-autotools-project@v1
+        with:
+          repository: wolfSSL/wolfssh
+          path: wolfssh
+          configure: --with-wolfssl=${{ github.workspace }}/build-dir
+          check: true