Add compile-only CI matrix entry for swtpm UART transport

Author: dgarske

.github/workflows/make-test-swtpm.yml

@@ -158,6 +158,11 @@ jobs:
             wolftpm_config: --disable-provisioning --disable-fwtpm
             needs_swtpm: false
 
+          # SWTPM UART transport (compile-only; no UART peer in CI)
+          - name: swtpm-uart
+            wolftpm_config: --enable-swtpm=uart --disable-fwtpm
+            needs_swtpm: false
+
           # Symmetric encryption
           - name: symmetric
             wolftpm_config: "--enable-swtpm --disable-fwtpm"