fix: resolve Go multi-file component compilation issues

- Include both main.go and utils.go in simple_test example to fix 'undefined function' errors
- Restore proper main.go path detection in TinyGo compilation logic
- TinyGo now correctly finds functions across multiple Go files in same package
- Multi-file test demonstrates proper multi-Go file component development
- Resolves CI build failures for Go components

Author: avrabe

examples/go_component/BUILD.bazel

@@ -90,10 +90,10 @@ go_wasm_component(
     world = "wasi:cli/command",
 )
 
-# Simple test without WIT bindings to isolate asyncify issues
+# Multi-file test demonstrating TinyGo compilation with multiple Go source files
 go_wasm_component(
     name = "simple_test",
-    srcs = ["main.go"],
+    srcs = ["main.go", "utils.go"],  # Include both main.go and utils.go
     adapter = "//wasm/adapters:wasi_snapshot_preview1",
     go_mod = "go.mod",
     optimization = "debug",