Use larger runners for Linux CI steps (#11574)

To speed up Linux CI builds, use a set of self-hosted Linux machines and
use them to run all slow CI steps for Linux: "tests", bundling and
nightly builds.

Also adds a set of dev icons as Linux bundling script required them for
`run-bundling`-tagged builds from regular PRs.
Same icons as for Preview were used, but, ideally, something different
could be created.

Release Notes:

- N/A

script/linux

@@ -1,12 +1,12 @@
-#!/usr/bin/bash
+#!/usr/bin/env bash
 
-set -e
+set -ex
 
 # Install our submodule dependencies
 git submodule update --init --recursive
 
 # install the wasm toolchain
-rustup target add wasm32-wasi
+which rustup > /dev/null 2>&1 || curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
 
 # if sudo is not installed, define an empty alias
 maysudo=$(command -v sudo || command -v doas || true)