ci: add memcached 1.6.22 to the test matrix

Author: m6w6

.github/workflows/cmake-build-ci.gen

@@ -398,7 +398,7 @@ jobs:
     continue-on-error: true
     strategy:
       matrix:
-        memcached: ['master', '1.6.17', '1.6.9', '1.5.22', '1.5.6']
+        memcached: ['master', '1.6.22', '1.6.17', '1.6.9', '1.5.22', '1.5.6']
     env:
       CMAKE_BUILD_TYPE:   "Debug"
       BUILD_TESTING:      "ON"

.github/workflows/cmake-build-ci.yml

@@ -122,7 +122,7 @@ jobs:
     continue-on-error: true
     strategy:
       matrix:
-        memcached: ['master', '1.6.17', '1.6.9', '1.5.22', '1.5.6']
+        memcached: ['master', '1.6.22', '1.6.17', '1.6.9', '1.5.22', '1.5.6']
     env:
       CMAKE_BUILD_TYPE:   "Debug"
       BUILD_TESTING:      "ON"