Fallback method for missing BYOND linux zips

.github/workflows/ci-pipeline.yml

@@ -111,6 +111,14 @@ jobs:
             VERSIONS=$(curl https://www.byond.com/download/version.txt)
             FULL_VERSION=$(echo "$VERSIONS" | tail -n1)
             echo "EDGE version evaluated to $FULL_VERSION"
+
+            # Also needs updating in ByondTest.cs
+            declare -A missing_linux_releases=([515.1612]="515.1611")
+
+            if [[ -n "${missing_linux_releases[$FULL_VERSION]}" ]] ; then
+                echo "$FULL_VERSION does not have a linux zip, falling back to ${missing_linux_releases[$FULL_VERSION]}"
+                FULL_VERSION=${missing_linux_releases[$FULL_VERSION]}
+            fi
         fi
         if [[ ! -f $HOME/byond-zips-cache/linux/$FULL_VERSION.zip ]] ; then
             BYOND_MAJOR=${FULL_VERSION%.*}