Updated Meteor version at Dockerfile.

Thanks to xet7 !

Dockerfile

@@ -22,7 +22,7 @@ ARG DEBIAN_FRONTEND=noninteractive
 ENV BUILD_DEPS="apt-utils libarchive-tools gnupg gosu wget curl bzip2 g++ build-essential git ca-certificates python3" \
     DEBUG=false \
     NODE_VERSION=v14.21.1 \
-    METEOR_RELEASE=2.7.3 \
+    METEOR_RELEASE=2.8.1 \
     USE_EDGE=false \
     METEOR_EDGE=1.5-beta.17 \
     NPM_VERSION=latest \