feat(yarn2): Enforce using the "node-modules" node linker

The Yarn 2 implementation requires that the "node-modules" node linker
[1] is used to filter out optional dependencies that were not installed.
Enforce that setting with the `YARN_NODE_LINKER` environment variable to
avoid the issue that no dependencies are found for projects that do not
set `nodeLinker=node-modules` in their `.yarnrc.yml`.

It has also been verified that the environment variable overrides any
different setting for `nodeLinker` in the `.yarnrc.yml`.

Also adapt the `.yarnrc.yml` files for all functional test projects as
they do not need to set `nodeLinker=node-modules` anymore.

[1]: https://yarnpkg.com/features/linkers

Signed-off-by: Martin Nonnenmacher <martin.nonnenmacher@bosch.com>

Author: mnonnenmacher

plugins/package-managers/node/src/funTest/assets/projects/synthetic/yarn2/dependency-with-patch/.yarnrc.yml

@@ -1,3 +1 @@
-nodeLinker: node-modules
-
 yarnPath: .yarn/releases/yarn-3.2.1.cjs

plugins/package-managers/node/src/funTest/assets/projects/synthetic/yarn2/project-with-lockfile/.yarnrc.yml

@@ -1,3 +1 @@
-nodeLinker: node-modules
-
 yarnPath: .yarn/releases/yarn-3.2.1.cjs

plugins/package-managers/node/src/funTest/assets/projects/synthetic/yarn2/workspaces/.yarnrc.yml

@@ -182,7 +182,16 @@ class Yarn2(override val descriptor: PluginDescriptor = Yarn2Factory.descriptor,
     }
 
     private fun installDependencies(workingDir: File) {
-        yarn2Command.run("install", workingDir = workingDir).requireSuccess()
+        yarn2Command.run(
+            "install",
+            workingDir = workingDir,
+            environment = mapOf(
+                // Set the node linker to "node-modules" as the "node_modules" directory is required by this class to
+                // filter out optional dependencies that were not installed.
+                // See: https://yarnpkg.com/features/linkers
+                "YARN_NODE_LINKER" to "node-modules"
+            )
+        ).requireSuccess()
     }
 
     private fun getPackageInfos(workingDir: File): List<PackageInfo> {