### Steps to reproduce

Hard to reproduce. It happens on community instance.

### What is the buggy behavior?

* Some users lose connection to Nexcloud, because OAuth tokens are removed suddenly.


### What is the expected behavior?

1. Nextcloud OAuth tokens live longer life.

2. And users do not need complete OAuth grant flow too often.


### Environment information

**OpenProject installation type**

* [x] Hosted cloud Begin of the insertionedition 

### Diagram showing concurrent request issue.

It shows that optimistic locking is not enough. <img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/198023/content">

Mermaid diagram source code.

```mermaidEnd of the insertion Begin of the deletion editionEnd of the deletion
Begin of the insertionsequenceDiagramEnd of the insertion Begin of the deletion * [ ] Packaged installationEnd of the deletion
Begin of the insertionparticipant OP1 as OpenProject Process 1
participant OP2 as OpenProject Process 2
participant OPDB as OpenProject DB
participant NC as Nextcloud

OP1->>OPDB: Get Token
OPDB->>OP1: Return Token!
OP2->>OPDB: Get Token
OPDB->>OP2: Return Token!
OP1->>NC: FileInfo Req
# Note over NC,OP1: A typical interaction
NC->>OP1: FileInfo Resp Auth Failed
OP1->>NC: RefreshToken Req
NC->>OP1: RefreshToken Resp Success

OP2->>NC: FileInfo Req
# Note over NC,OP1: A typical interaction
NC->>OP2: FileInfo Resp Auth Failed

OP2->>NC: RefreshToken Req
NC->>OP2: RefreshToken Resp Failed

OP2->>OPDB: Destroy Token
OPDB->>OP2: Destroy Token Success
Note over OP2,OPDB: Success due to nothing to prevent that. <br>Optimistic lock does not help.

OP1->>OPDB: Update Token
OPDB->>OP1: Update Token Failure
Note over OP1,OPDB: Failure because token has been destroyed. <br> ActiveRecord::StaleObject if optimistic locking is on.

OP2->>OP2: Return unauthorized response
OP1->>OP1: Return 409 Conflict responseEnd of the insertion Begin of the deletion * What distribution?

* [ ] Docker All-in-one containerEnd of the deletion
Begin of the insertion```End of the insertion Begin of the deletion * [ ] Docker-compose installation
* [ ] Other (please specify)End of the deletion