Update actions/cache action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/cache	action	major	v3 -> v4

---

Release Notes

actions/cache (actions/cache)

### [`v4`](https://togithub.com/actions/cache/compare/v3...v4) [Compare Source](https://togithub.com/actions/cache/compare/v3...v4)

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.

[github-actions[bot]]

Jar size:

Jar size change: +0.0B (3.1MiB -> 3.1MiB)

Diffuse output:

OLD: diffuse-source-file
NEW: pull-request-artifact.jar

       │         compressed         │         uncompressed         
       ├──────────┬──────────┬──────┼───────────┬───────────┬──────
 JAR   │ old      │ new      │ diff │ old       │ new       │ diff 
───────┼──────────┼──────────┼──────┼───────────┼───────────┼──────
 class │ 55.2 KiB │ 55.2 KiB │  0 B │ 117.5 KiB │ 117.5 KiB │  0 B 
 other │    3 MiB │    3 MiB │  0 B │   6.4 MiB │   6.4 MiB │  0 B 
───────┼──────────┼──────────┼──────┼───────────┼───────────┼──────
 total │  3.1 MiB │  3.1 MiB │  0 B │   6.5 MiB │   6.5 MiB │  0 B 

 CLASSES │ old │ new │ diff      
─────────┼─────┼─────┼───────────
 classes │  24 │  24 │ 0 (+0 -0) 
 methods │ 630 │ 630 │ 0 (+0 -0) 
  fields │  67 │  67 │ 0 (+0 -0)