common: restapi : fix bug at endpoint /api/fw_versions

Summary:
# Description
- import and use Tuple insteads tuple in rest_fw_versions.py
- get `bash` real path insteads fixing in source code

# Motivation
Fix bug the restapi failed on start
```
root@bmc-oob:~# rest.py
Traceback (most recent call last):
  File "/usr/local/bin/rest.py", line 38, in <module>
    from setup_plat_routes import setup_plat_routes
  File "/usr/local/fbpackages/rest-api/setup_plat_routes.py", line 23, in <module>
    from board_setup_routes import setup_board_routes
  File "/usr/local/fbpackages/rest-api/board_setup_routes.py", line 22, in <module>
    from board_endpoint import boardApp_Handler
  File "/usr/local/fbpackages/rest-api/board_endpoint.py", line 26, in <module>
    import rest_fw_versions
  File "/usr/local/fbpackages/rest-api/rest_fw_versions.py", line 50, in <module>
    def _run_command(cmd: str) -> tuple[str, str]:
TypeError: 'type' object is not subscriptable
```

fix bug `/usr/local/bash` path not found
```
root@bmc-oob:~# curl http://localhost:8080/api/fw_versions | python -m json.tool
{
    "Information": {
        "firmware_versions": {
            "bic": "",
            "bios": "",
            "fcm": "",
            "fpga": "",
            "pwr": "",
            "scm": "",
            "smb": ""
        },
        "firmware_string": "bic:,bios:,fcm:,fpga:,pwr:,scm:,smb:",
        "firmware_hash": "369bbdb4c097",
        "errors": {
            "bic": "Command exception: /usr/bin/fw-util scm --version |grep Bri|grep -v Boot| cut -d ' ' -f 3 - FileNotFoundError(2, 'No such file or directory')",
            "bios": "Command exception: /usr/bin/fw-util scm --version |grep BIOS| cut -d ' ' -f 3 - FileNotFoundError(2, 'No such file or directory')",
            "fcm": "Command exception: /usr/local/bin/cpld_ver.sh |grep FCM|cut -d ' ' -f 2 - FileNotFoundError(2, 'No such file or directory')",
            "fpga": "Command exception: /usr/local/bin/fpga_ver.sh |grep FPGA|head -1|cut -d ' ' -f 2 - FileNotFoundError(2, 'No such file or directory')",
            "pwr": "Command exception: /usr/local/bin/cpld_ver.sh |grep PWR|cut -d ' ' -f 2 - FileNotFoundError(2, 'No such file or directory')",
            "scm": "Command exception: /usr/local/bin/cpld_ver.sh |grep SCM|cut -d ' ' -f 2 - FileNotFoundError(2, 'No such file or directory')",
            "smb": "Command exception: /usr/local/bin/cpld_ver.sh |grep SYSCPLD|cut -d ' ' -f 2 - FileNotFoundError(2, 'No such file or directory')"
        }
    },
    "Actions": [],
    "Resources": []
}
```

X-link: https://github.com/facebookexternal/openbmc.celestica/pull/1903

Test Plan:
Test on wedge400
```
root@bmc-oob:~# curl http://localhost:8080/api/sys
{"Information": {"Description": "Wedge System"}, "Actions": [], "Resources": ["bmc", "board_revision", "fc_present", "feutil", "firmware_info", "fscd_sensor_data", "gb_freq", "gpios", "mb", "modbus", "modbus_registers", "ntp", "optics_thermal", "presence", "psu_update", "sensors", "server", "seutil", "switch_reset", "vddcore"]}
```

```
root@bmc-oob:~# curl http://localhost:8080/api/fw_versions | python -m json.tool
{
    "Information": {
        "firmware_versions": {
            "bic": "1.15",
            "bios": "XG1_3A12",
            "fcm": "4.2",
            "fpga": "0.56",
            "pwr": "2.4",
            "scm": "4.0",
            "smb": "2.5"
        },
        "firmware_string": "bic:1.15,bios:XG1_3A12,fcm:4.2,fpga:0.56,pwr:2.4,scm:4.0,smb:2.5",
        "firmware_hash": "a45435f67303",
        "errors": {}
    },
    "Actions": [],
    "Resources": []
}
root@bmc-oob:~#
```

Reviewed By: binhuang00

Differential Revision: D90559411

Pulled By: ezeob002

fbshipit-source-id: faa33f2216446e5ed2708d65e23f78e62fc0df58

Author: ssinprem

common/recipes-rest/rest-api/files/rest_fw_versions.py

@@ -21,12 +21,14 @@
 import hashlib
 import json
 import re
+import shutil
 import subprocess
-from typing import Dict
+from typing import Dict, Tuple
 
 from aiohttp.web_exceptions import HTTPNotFound
 from rest_utils import DEFAULT_TIMEOUT_SEC
 
+_BASH_PATH = shutil.which("bash")
 _REGEX_VERSION_PATTERN = r"^[v]?([0-9]*)\.([0-9]*)$"
 _MANIFEST_FILE = "/etc/ufw_manifest.json"
 
@@ -47,13 +49,15 @@ def _normalize_version(version: str) -> str:
     return version
 
 
-def _run_command(cmd: str) -> tuple[str, str]:
+def _run_command(cmd: str) -> Tuple[str, str]:
     """
     Run a shell command and return (stdout, error_message).
     """
     try:
+        if not _BASH_PATH:
+            return "", "bash executable not found"
         proc = subprocess.Popen(
-            ["/usr/bin/bash", "-o", "pipefail", "-c", cmd],
+            [_BASH_PATH, "-o", "pipefail", "-c", cmd],
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
         )
@@ -87,7 +91,7 @@ def _check_condition(condition: str, entity: str) -> bool:
     return proc.returncode == 0
 
 
-def _get_firmware_versions() -> tuple[Dict[str, str], Dict[str, str]]:
+def _get_firmware_versions() -> Tuple[Dict[str, str], Dict[str, str]]:
     """
     Get all firmware versions and return as tuple of dicts.
     fw_key: version, fw_key: error (if applicable)