Build sherpa-onnx as a single shared library (#1078)

When `-D BUILD_SHARED_LIBS=ON` is passed to `cmake`, it builds a single shared library.

Specifically, 

- For C APIs, it builds `libsherpa-onnx-c-api.so`
- For Python APIs, it builds `_sherpa_onnx.cpython-xx-xx.so`
- For Kotlin and Java APIs, it builds `libsherpa-onnx-jni.so`

There is no `libsherpa-onnx-core.so` any longer.

Note it affects only shared libraries.

scripts/dart/release.sh

@@ -44,10 +44,6 @@ function process_linux() {
 
   pushd linux
 
-  rm -v libpiper_phonemize.so libpiper_phonemize.so.1.2.0
-  rm -v libonnxruntime.so
-  rm -v libcargs.so
-
   popd
 }
 
@@ -69,12 +65,6 @@ function process_macos() {
   cp -v sherpa_onnx/lib/*.dylib ../macos
   cd ..
   rm -rf t
-
-  pushd macos
-  rm -v libcargs.dylib
-  rm -v libonnxruntime.dylib
-  rm -v libpiper_phonemize.1.2.0.dylib libpiper_phonemize.dylib
-  popd
 }
 
 process_linux