psalm: test against the correct server version

Signed-off-by: Robin Appelman <robin@icewind.nl>

Author: icewind1991

.github/workflows/psalm-matrix.yml

@@ -24,7 +24,7 @@ jobs:
       # do not stop on another job's failure
       fail-fast: false
       matrix:
-        ocp-version: [ 'dev-stable26', 'dev-stable25', 'dev-stable24' ]
+        ocp-version: [ 'dev-stable26' ]
 
     name: Nextcloud ${{ matrix.ocp-version }}
     steps: