build: add script to publish v10-lts releases (angular#41631)

Adds a `/scripts/release/publish` script for releasing 10.2.x. Also
removes scripts for publishing `latest` and `next`. We are no longer
releasing `latest` and `next` off of this branch. This branch is only
for `v10-lts` releases.

PR Close angular#41631

Author: zarend

scripts/release/post-check-next

@@ -24,5 +24,5 @@ $BAZEL build --config=release $NPM_PACKAGE_LABELS
 # publish all packages in sequence to make it easier to spot any errors or warnings
 for packageLabel in $NPM_PACKAGE_LABELS; do
   echo "publishing $packageLabel"
-  $BAZEL run --config=release -- ${packageLabel}.publish --access public --tag latest
+  $BAZEL run --config=release -- ${packageLabel}.publish --access public --tag v10-lts
 done