refactor(scripts): switch from bash to sh for enhanced portability

	•	Updated all scripts (action.sh, check.sh, deploy.sh, post_action.sh, post_check.sh) to use sh instead of bash.
	•	Ensured compatibility across environments by replacing bash-specific syntax with POSIX-compliant alternatives.
	•	Improved maintainability by standardizing the shebang to #!/usr/bin/env sh.

Author: warnyul

action.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 set -e
 

check.sh

@@ -1,6 +1,6 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
-if [[ ! -s ~/.ssh/known_hosts ]]; then
+if [ ! -s ~/.ssh/known_hosts ]; then
     echo "::error file=$(basename "$0"),line=${LINENO},endLine=${LINENO},title=Assertion Error::\
 ~/.ssh/known_hosts is missing or empty."
     exit 1

deploy.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 # renovate: datasource=docker depname=traefik/whoami versioning=docker
 WHOAMI_VERSION="43a68d10b9dfcfc3ffbfe4dd42100dc9aeaf29b3a5636c856337a5940f1b4f1c" # v1.10

post_action.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
 if [ -z "${SSH_KNOWN_HOSTS_FILE}" ]; then
     echo "::error file=$(basename "$0"),line=${LINENO},endLine=${LINENO},title=Notice::\

post_check.sh

@@ -1,6 +1,6 @@
-#!/usr/bin/env bash
+#!/usr/bin/env sh
 
-if [[ -s ~/.ssh/known_hosts ]]; then
+if [ -s ~/.ssh/known_hosts ]; then
     echo "::error file=$(basename "$0"),line=${LINENO},endLine=${LINENO},title=Assertion Error::\
 ~/.ssh/known_hosts file should not exist after the job."
     exit 1