.github/workflows/ci.yml: bypass Go build if the compiler is not pres…

…ent.

.github/workflows/ci.yml

@@ -154,7 +154,7 @@ jobs:
     - name: Go
       shell: bash
       run: |
-        go version
+        go version 2>/dev/null || exit 0
         if ! (grep -q -e '^flags.*\badx\b' /proc/cpuinfo) 2>/dev/null; then
             export CGO_CFLAGS="-O -D__BLST_PORTABLE__"
         fi