Bump axios and pm2

Removes [axios](https://github.com/axios/axios). It's no longer used after updating ancestor dependency [pm2](https://github.com/Unitech/pm2). These dependencies need to be updated together.


Removes `axios`

Updates `pm2` from 5.2.2 to 5.3.1
- [Release notes](https://github.com/Unitech/pm2/releases)
- [Changelog](https://github.com/Unitech/pm2/blob/master/CHANGELOG.md)
- [Commits](Unitech/pm2@5.2.2...v5.3.1)

---
updated-dependencies:
- dependency-name: axios
  dependency-type: indirect
- dependency-name: pm2
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -37,7 +37,7 @@
         "mqtt": "^4.3.7",
         "mysql": "^2.18.1",
         "net": "^1.0.2",
-        "pm2": "^5.2.2",
+        "pm2": "^5.3.1",
         "sequelize": "^6.33.0",
         "util": "^0.12.5"
     },