chore: remove obsolete Jest config and unit test global setup (#4044)

The files were overlooked during the migration from jest to vitest
(#3940).

jest.config.js

@@ -1,41 +0,0 @@
-const aliasMapper = {
-	logger: "<rootDir>/js/logger.js"
-};
-
-const config = {
-	verbose: true,
-	testTimeout: 20000,
-	testSequencer: "<rootDir>/tests/utils/test_sequencer.js",
-	projects: [
-		{
-			displayName: "unit",
-			globalSetup: "<rootDir>/tests/unit/helpers/global-setup.js",
-			moduleNameMapper: aliasMapper,
-			testMatch: ["**/tests/unit/**/*.[jt]s?(x)"],
-			testPathIgnorePatterns: ["<rootDir>/tests/unit/mocks", "<rootDir>/tests/unit/helpers"]
-		},
-		{
-			displayName: "electron",
-			testMatch: ["**/tests/electron/**/*.[jt]s?(x)"],
-			moduleNameMapper: aliasMapper,
-			testPathIgnorePatterns: ["<rootDir>/tests/electron/helpers"]
-		},
-		{
-			displayName: "e2e",
-			testMatch: ["**/tests/e2e/**/*.[jt]s?(x)"],
-			modulePaths: ["<rootDir>/js/"],
-			moduleNameMapper: aliasMapper,
-			testPathIgnorePatterns: ["<rootDir>/tests/e2e/helpers", "<rootDir>/tests/e2e/mocks"]
-		}
-	],
-	collectCoverageFrom: [
-		"<rootDir>/clientonly/**/*.js",
-		"<rootDir>/js/**/*.js",
-		"<rootDir>/defaultmodules/**/*.js",
-		"<rootDir>/serveronly/**/*.js"
-	],
-	coverageReporters: ["lcov", "text"],
-	coverageProvider: "v8"
-};
-
-module.exports = config;

tests/unit/helpers/global-setup.js

@@ -1,3 +0,0 @@
-module.exports = () => {
-	process.env.TZ = "UTC";
-};