Test with Ruby 3.4 on CI

Author: ankane

.github/workflows/build.yml

@@ -7,7 +7,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 3.3
+          ruby-version: 3.4
           bundler-cache: true
       - uses: ankane/setup-postgres@v1
         with:

lib/pgvector/vector.rb

@@ -30,7 +30,7 @@ def to_a
 
     def to_binary
       if numo?(@data)
-        [@data.shape[0], 0].pack("s>s>") + @data.to_network.to_binary
+        [@data.shape[0], 0].pack("s>s>") + @data.to_network.to_binary.force_encoding(Encoding::BINARY)
       else
         buffer = [@data.size, 0].pack("s>s>")
         @data.pack("g*", buffer: buffer)