Enable bash scr to to be path-independent using $0 to address ERROR: …

…failed to solve: failed to read dockerfile: open Dockerfile.intel_hpu: no such file or director when following README (opea-project#808)

Signed-off-by: Qun Gao <qun.gao@intel.com>
Co-authored-by: ZePan110 <ze.pan@intel.com>
Co-authored-by: Abolfazl Shahbazi <12436063+ashahba@users.noreply.github.com>

comps/llms/text-generation/vllm/langchain/dependency/build_docker_vllm.sh

@@ -14,6 +14,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# Get script directory
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+echo "Script directory: $SCRIPT_DIR"
+cd $SCRIPT_DIR
+
 # Set default values
 default_hw_mode="cpu"