chore: keycard mocked lib is false by default

Disabling to build Linux artefacts with Keycard mock lib, as it may be the cause of tests being stuck

ci/Jenkinsfile.linux

@@ -34,7 +34,7 @@ pipeline {
     booleanParam(
       name: 'USE_MOCKED_KEYCARD_LIB',
       description: 'Decides whether the mocked status-keycard-go library is built.',
-      defaultValue: getMockedKeycardLibDefault()
+      defaultValue: false
     )
   }
 
@@ -130,7 +130,3 @@ def getArch() {
     if (tokens.contains(arch)) { return arch }
   }
 }
-
-def getMockedKeycardLibDefault() {
-  return utils.isReleaseBuild() ? 'false' : 'true'
-}