Bugfix concat path

[trondth]

No description provided.

[github-actions]

Triggered from #163 by @​trondth.

Checking if we can fast forward master (a6bda19) to bugfix_concat_path (7b92ca7).

Target branch (master):

commit a6bda19c5d0a28fbe939a88890674f9a9fcb6012 (HEAD -> master, origin/master, origin/HEAD)
Author: Trond Thorbjørnsen <trond.thorbjornsen@usit.uio.no>
Date:   Wed Jan 15 11:00:52 2025 +0100

    use pathlib for concatenating paths

Pull request (bugfix_concat_path):

commit 7b92ca76d6d345648dd33026b491e130420fc165 (pull_request/bugfix_concat_path)
Author: Trond Thorbjørnsen <trond.thorbjornsen@usit.uio.no>
Date:   Wed Jan 15 15:51:25 2025 +0100

    fix concatenation for resumables

Can't fast forward master (a6bda19) to bugfix_concat_path (7b92ca7). master (a6bda19) is not a direct ancestor of bugfix_concat_path (7b92ca7). Branches appear to have diverged at 7395aaf:

* 7b92ca76d6d345648dd33026b491e130420fc165 fix concatenation for resumables
* 7545e9213dd3550c9cf4a5b0ce3a3a3a6a4fdaf6 use pathlib for concatenating paths
| * a6bda19c5d0a28fbe939a88890674f9a9fcb6012 use pathlib for concatenating paths
|/  
* 7395aaf8382e82d80127cf04d6f0352150c77c32 fix: Switch to using Optional to preserve compatibility with 3.9

commit 7395aaf8382e82d80127cf04d6f0352150c77c32 (tag: v3.6.3)
Author: Milen Kouylekov <milen.kouylekov@usit.uio.no>
Date:   Wed Nov 6 12:57:47 2024 +0100

    fix: Switch to using Optional to preserve compatibility with 3.9

Rebase locally, and then force push to bugfix_concat_path.