Bump tar from 4.4.13 to 4.4.15 in /backend

Bumps [tar](https://github.com/npm/node-tar) from 4.4.13 to 4.4.15.
- [Release notes](https://github.com/npm/node-tar/releases)
- [Changelog](https://github.com/npm/node-tar/blob/main/CHANGELOG.md)
- [Commits](https://github.com/npm/node-tar/compare/v4.4.13...v4.4.15)

---
updated-dependencies:
- dependency-name: tar
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

backend/yarn.lock

@@ -3351,9 +3351,9 @@ table@^5.2.3:
     string-width "^3.0.0"
 
 tar@^4, tar@^4.4.2:
-  version "4.4.13"
-  resolved "https://registry.yarnpkg.com/tar/-/tar-4.4.13.tgz#43b364bc52888d555298637b10d60790254ab525"
-  integrity sha512-w2VwSrBoHa5BsSyH+KxEqeQBAllHhccyMFVHtGtdMpF4W7IRWfZjFiQceJPChOeTsSDVUpER2T8FA93pr0L+QA==
+  version "4.4.15"
+  resolved "https://registry.yarnpkg.com/tar/-/tar-4.4.15.tgz#3caced4f39ebd46ddda4d6203d48493a919697f8"
+  integrity sha512-ItbufpujXkry7bHH9NpQyTXPbJ72iTlXgkBAYsAjDXk3Ds8t/3NfO5P4xZGy7u+sYuQUbimgzswX4uQIEeNVOA==
   dependencies:
     chownr "^1.1.1"
     fs-minipass "^1.2.5"