fix: Shebang content

1. Change Shebang from absolute path to logical path, which can adapt to
   more situations.

install-dat-release.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This Bash script to install the latest release of geoip.dat and geosite.dat:
 

install-release.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # The files installed by the script conform to the Filesystem Hierarchy Standard:
 # https://wiki.linuxfoundation.org/lsb/fhs