kvserver: Replica.Send write path ctx cancellation doesn't work when disk stalled

**Describe the problem**

When the leaseholder's disk is stalled and a client that is waiting for a write has its ctx canceled, we don't return from `Replica.Send`. This is because the call to `abandon` here:

https://github.com/cockroachdb/cockroach/blob/b4216ac71b92c5014d10f84db89f1542033c86f6/pkg/kv/kvserver/replica_raft.go#L307-L310

tries to acquire `raftMu`, but `raftMu` is with near certainty held by the raft processing goroutine for the range which will be stuck on the disk.

**To Reproduce**

https://github.com/cockroachdb/cockroach/pull/98852 TestWriteWithStuckLeaseholderDisk

**Expected behavior**

Ctx cancellation is obeyed.

Jira issue: CRDB-39894