Use portable shebang for all bash scripts

Refs #426 <https://github.com/Genymobile/scrcpy/pull/426>
Refs #1716 <https://github.com/Genymobile/scrcpy/pull/1716>

prebuilt-deps/prepare-dep

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 url="$1"
 sum="$2"

run

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Run scrcpy generated in the specified BUILDDIR.
 #
 # This provides the same feature as "ninja run", except that it is possible to

scripts/run-scrcpy.sh

@@ -1,2 +1,2 @@
-#!/bin/bash
+#!/usr/bin/env bash
 SCRCPY_SERVER_PATH="$MESON_BUILD_ROOT/server/scrcpy-server" "$MESON_BUILD_ROOT/app/scrcpy"