test: restore the environment before each msvc test

src/msvc/__tests__/msvc.test.ts

@@ -2,8 +2,14 @@ import which from "which"
 import { testBin } from "../../utils/tests/test-helpers"
 import { setupMSVC } from "../msvc"
 
+const initial_env = { ...process.env }
+
 jest.setTimeout(300000)
 describe("setup-msvc", () => {
+  beforeEach(() => {
+    process.env = initial_env
+  })
+
   it("should setup msvc 2019", async () => {
     if (process.platform !== "win32") {
       return