tree-wide: replace /bin/bash with /usr/bin/env bash

The latter is more portable, while the former only works on systems
where /bin/bash exists (or is symlinked appropriately).

bin/backend-versions.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # This adds the version each backend was released to its docs page
 set -e
 for backend in $( find backend -maxdepth 1 -type d ); do

bin/bisect-go-rclone.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # An example script to run when bisecting go with git bisect -run when
 # looking for an rclone regression

bin/bisect-rclone.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # Example script for git bisect run
 #

bin/build-xgo-cgofuse.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 docker build -t rclone/xgo-cgofuse https://github.com/winfsp/cgofuse.git
 docker images

bin/make_rc_docs.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Insert the rc docs into docs/content/rc.md
 
 set -e

bin/test-repeat-vfs.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Thrash the VFS tests
 
 set -e

bin/test-repeat.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # defaults
 buildflags=""

bin/use-deadlock-detector

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 if [[ ! -z $(git status --short --untracked-files=no) ]]; then
    echo "Detected uncommitted changes - commit before running this"