Fix CI dependency conflict and libgomp path on Ubuntu

- Add --update-invariant to opam install for flambda compatibility
- Add Ubuntu x86_64 path for libgomp.a in dune rule

Author: taoeffect

.github/workflows/test.yml

@@ -25,7 +25,7 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y npm xz-utils libomp-dev llvm-dev
-          opam install . --deps-only
+          opam install . --deps-only --update-invariant
           npm install --no-save typescript browserify pug-lexer pug-parser pug-walk
 
       - name: Install QuickJS

src/quickjs/dune

@@ -55,6 +55,7 @@
   (action (bash "
     cp /usr/local/Cellar/libomp/17.0.6/lib/libomp.a . &> /dev/null \
     || cp /usr/lib/libgomp.a libomp.a &> /dev/null \
+    || cp /usr/lib/gcc/x86_64-linux-gnu/*/libgomp.a libomp.a &> /dev/null \
     || cp /usr/lib/gcc/aarch64-redhat-linux/15/libgomp.a libomp.a
   "))
   (mode standard)