dev(ci): complete refactor

Nearly completely replace the original GitHub actions workflow.
Changes:

- Move from `.sh` files in `ci/steps` to steps in the workflow.
- Move from using docker images for environment to manual setup.
- Upgrade nfpm to v2.3.1

BREAKING CHANGE: official arm64 builds no longer support CentOS 7.
If you need to use CentOS 7 on arm64, build `code-server` locally.
For docs, see the yarn/npm section in `docs/install.md`.

docs/install.md

@@ -89,6 +89,9 @@ commands presented in the rest of this document.
 
 ## Debian, Ubuntu
 
+NOTE: The standalone arm64 .deb does not support Ubuntu <16.04.
+Please upgrade or [build with yarn](#yarn-npm).
+
 ```bash
 curl -fOL https://github.com/cdr/code-server/releases/download/v3.9.2/code-server_3.9.2_amd64.deb
 sudo dpkg -i code-server_3.9.2_amd64.deb
@@ -98,6 +101,9 @@ sudo systemctl enable --now code-server@$USER
 
 ## Fedora, CentOS, RHEL, SUSE
 
+NOTE: The standalone arm64 .rpm does not support CentOS 7.
+Please upgrade or [build with yarn](#yarn-npm).
+
 ```bash
 curl -fOL https://github.com/cdr/code-server/releases/download/v3.9.2/code-server-3.9.2-amd64.rpm
 sudo rpm -i code-server-3.9.2-amd64.rpm
@@ -157,8 +163,8 @@ For more context, see [comment](https://github.com/cdr/code-server/issues/1730#i
 We recommend installing with `yarn` or `npm` when:
 
 1. You aren't on `amd64` or `arm64`.
-2. If you're on Linux with glibc < v2.17 or glibcxx < v3.4.18
-3. You're running Alpine Linux. See [#1430](https://github.com/cdr/code-server/issues/1430#issuecomment-629883198)
+2. If you're on Linux with glibc < v2.17 or glibcxx < v3.4.18 on amd64, or glibc < v2.23 or glibcxx < v3.4.21 on arm64.
+3. You're running Alpine Linux, or are using a non-glibc libc. See [#1430](https://github.com/cdr/code-server/issues/1430#issuecomment-629883198)
 
 **note:** Installing via `yarn` or `npm` builds native modules on install and so requires C dependencies.
 See [./npm.md](./npm.md) for installing these dependencies.