Add a --wasm test shard in master.

.ci.yaml

@@ -888,6 +888,20 @@ targets:
           "PACKAGE_SHARDING": "--shardIndex 2 --shardCount 3"
         }
 
+  # Wasm tests in master. Do these need any sharding?
+  - name: Linux_web web_platform_tests_wasm master
+    bringup: true
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests_wasm.yaml
+      version_file: flutter_master.version
+      channel: master
+      env_variables: >-
+        {
+          "CHANNEL": "master",
+        }
+
   - name: Linux_web web_platform_tests_shard_1 stable
     recipe: packages/packages
     timeout: 60

script/configs/exclude_all_packages_app_wasm.yaml

@@ -1,8 +1,8 @@
 # This list should be kept as short as possible, and things should remain here
 # only as long as necessary, since in general the goal is for all of the latest
 # versions of packages to be mutually compatible, and compilable with Wasm.
-
-# This is only used for wasm compilation. Once all packages in the repo have
-# been migrated, remove this file and use `exclude_all_packages_app.yaml` only.
+#
+# This is only used for the rare case where a package fails in Wasm, but works
+# in JS mode.
 
 [] # Needed so the contents of this file are an empty array, not `null`!

script/configs/exclude_integration_web_wasm.yaml

@@ -0,0 +1,8 @@
+# This list should be kept as short as possible, and things should remain here
+# only as long as necessary, since in general all web packages should work with
+# Wasm.
+#
+# This is only used for the rare case where a package fails in Wasm, but works
+# in JS mode.
+
+[] # Needed so the contents of this file are an empty array, not `null`!