Remove gno build command

`gno build` has been removed from gno binary in PR[1]. Removed usage
of same in the language server.

Using `gno precompile -gobuild` instead.

See:
[1]: gnolang/gno@0c68394)
[2]: gnolang/gno#1242

internal/tools/build.go

@@ -5,7 +5,8 @@ import (
 	"path/filepath"
 )
 
-// Build a Gno package: gno build <dir>.
+// Build a Gno package: gno precompile -gobuild <dir>.
+// TODO: Remove this in the favour of directly using tools/precompile.go
 func Build(rootDir string) ([]byte, error) {
-	return exec.Command("gno", "build", filepath.Join(rootDir)).CombinedOutput()
+	return exec.Command("gno", "precompile", "-gobuild", filepath.Join(rootDir)).CombinedOutput()
 }