[ci] Add LUCI version of build-all for web (flutter#4232)

Adds a new Linux_web configuration, and an initial test (build-all-packages) using it.

This is the simplest web test since it doesn't actually run anything, so starting with this one as a foundation to test future web-based tests.

Part of flutter#114373

Author: stuartmorgan-g

.ci.yaml

@@ -24,6 +24,15 @@ platform_properties:
           {"dependency": "ninja", "version": "version:1.9.0"},
           {"dependency": "curl", "version": "version:7.64.0"}
         ]
+  linux_web:
+    properties:
+      os: Ubuntu
+      cores: "8"
+      device_type: none
+      dependencies: >-
+        [
+          {"dependency": "chrome_and_driver", "version": "version:114.0"}
+        ]
   windows:
     properties:
       dependencies: >
@@ -70,6 +79,25 @@ targets:
       channel: master
       version_file: flutter_master.version
 
+  ### Web tasks ###
+  - name: Linux_web web_build_all_packages master
+    bringup: true # New target
+    recipe: packages/packages
+    timeout: 30
+    properties:
+      version_file: flutter_master.version
+      target_file: web_build_all_packages.yaml
+      channel: master
+
+  - name: Linux_web web_build_all_packages stable
+    bringup: true # New target
+    recipe: packages/packages
+    timeout: 30
+    properties:
+      version_file: flutter_stable.version
+      target_file: web_build_all_packages.yaml
+      channel: stable
+
   ### Linux desktop tasks
   - name: Linux_desktop build_all_packages master
     bringup: true # New target

.ci/targets/web_build_all_packages.yaml

@@ -0,0 +1,10 @@
+tasks:
+  - name: prepare tool
+    script: .ci/scripts/prepare_tool.sh
+  - name: create all_packages app
+    script: .ci/scripts/create_all_packages_app.sh
+  # No debug version, unlike the other platforms, since web does not support
+  # debug builds.
+  - name: build all_packages app for Web release
+    script: .ci/scripts/build_all_packages_app.sh
+    args: ["web", "release"]