Dont try downgrade test for pg18 packages

Since there is only 1 version for pg18 we cant do downgrade test
atm.

Author: svenklemm

.github/workflows/apt-arm-packages.yaml

@@ -22,6 +22,9 @@ jobs:
       matrix:
         image: [ "debian:11-slim", "debian:12-slim", "debian:13-slim", "ubuntu:22.04", "ubuntu:24.04" ]
         pg: [ 15, 16, 17, 18 ]
+        exclude:
+          - image: "debian:11-slim"
+            pg: 18
 
     steps:
     - name: Setup emulation

.github/workflows/apt-packages.yaml

@@ -30,6 +30,10 @@ jobs:
         include:
           - license: Apache
             pkg_suffix: "-oss"
+        exclude:
+          - image: "debian:11-slim"
+            pg: 18
+
 
     steps:
     - name: Add repositories
@@ -90,7 +94,7 @@ jobs:
         fi
 
     - name: Test Downgrade
-      if: matrix.image != 'debian:13-slim' # debian 13 only has timescaledb 2.22.0+ so we can only start testing downgrades with 2.22.1+
+      if: matrix.pg != '18' # pg18 only has 1 version so downgrade is not possible
       run: |
         # Since this runs nightly on main we have to get the previous version
         # from the last released version and not current branch.

.github/workflows/rpm-packages.yaml

@@ -29,6 +29,9 @@ jobs:
         include:
           - license: Apache
             pkg_suffix: "-oss"
+        exclude:
+          - image: "rockylinux:8"
+            pg: 18
 
     steps:
     - name: Add postgres repositories
@@ -93,6 +96,7 @@ jobs:
         fi
 
     - name: Test Downgrade
+      if: matrix.pg != '18' # pg18 only has 1 version so downgrade is not possible
       run: |
         # Since this runs nightly on main we have to get the previous version
         # from the last released version and not current branch.