Updated CI

Author: ankane

.github/workflows/build.yml

@@ -7,14 +7,14 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ocaml/setup-ocaml@v2
         with:
-          ocaml-compiler: 4.14
+          ocaml-compiler: 5
       - uses: ankane/setup-postgres@v1
         with:
           database: pgvector_ocaml_test
           dev-files: true
       - run: |
           cd /tmp
-          git clone --branch v0.8.0 https://github.com/pgvector/pgvector.git
+          git clone --branch v0.8.1 https://github.com/pgvector/pgvector.git
           cd pgvector
           make
           sudo make install