feat(ci): publish dev builds to @coder/code-server-pr (#4972)

* feat(npm): use DEV_PACKAGE_NAME for development

* feat(ci): use npm v7 in npm job

* fixup: add npm version

* fixup: always set package name

* wip

* fix: check for npm and npm v7

* fixup

* fixup: move after release dir created

* fixup: use jq

* fixup: use jq correctly