Removes integration_test/vs (#2270)

vs was introduced to bench various things including
the tests against other runtimes. However, the
cases are not representative, and also some are
just unable to build plus some are simply failing.

This removes the entire vs directory, and reduces
the maintenance burden.

Signed-off-by: Takeshi Yoneda <t.y.mathetake@gmail.com>

cache_test.go

@@ -14,10 +14,10 @@ import (
 	"github.com/tetratelabs/wazero/internal/wasm"
 )
 
-//go:embed internal/integration_test/vs/testdata/fac.wasm
+//go:embed testdata/fac.wasm
 var facWasm []byte
 
-//go:embed internal/integration_test/vs/testdata/mem_grow.wasm
+//go:embed testdata/mem_grow.wasm
 var memGrowWasm []byte
 
 func TestCompilationCache(t *testing.T) {