ci: try to fix compliance workflow

ubuntu-latest points to 24.04 - use ubuntu 22.04 now

Signed-off-by: Kari Hamalainen <kari.hamalainen@nordicsemi.no>

.github/workflows/compliance.yml

@@ -4,7 +4,7 @@ on: pull_request
 
 jobs:
   compliance_job:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     name: Run compliance checks on patch series (PR)
     steps:
     - name: Checkout the code
@@ -30,7 +30,6 @@ jobs:
         pip3 install -U yamllint
         pip3 install lxml==4.9.1
         pip3 install  -U python-magic junitparser==2.8.0 gitlint pylint pykwalify
-        pip3 install -U unidiff
         pip3 install --user -U west
         pip3 show -f west