Don't fail when SSH_KNOWN_HOSTS is undefined.

src/scripts/gitlab-ci.ts

@@ -19,6 +19,7 @@ const {
   CI_MERGE_REQUEST_SOURCE_BRANCH_NAME,
   CI_MERGE_REQUEST_TARGET_BRANCH_NAME,
   CI_PIPELINE_SOURCE,
+  SSH_KNOWN_HOSTS,
   SSH_PRIVATE_KEY,
 } = process.env
 
@@ -55,6 +56,7 @@ async function configureSsh() {
     await $`echo "$SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add -`
   }
 
+  if (SSH_KNOWN_HOSTS !== undefined) {
     // Create the SSH directory and give it the right permissions
     await $`mkdir -p ~/.ssh`
     await $`chmod 700 ~/.ssh`
@@ -62,6 +64,7 @@ async function configureSsh() {
     await $`echo "$SSH_KNOWN_HOSTS" > ~/.ssh/known_hosts`
     await $`chmod 644 ~/.ssh/known_hosts`
   }
+}
 
 async function createNewBranchWithUpdatedVersions() {
   // Ensure that everything works.