Make tests hermetic by using FixtureServer instead of real hostnames

- testWorkspaceIdFromEnvironmentVariables: use FixtureServer URL
  instead of https://mycompany.databricks.com to avoid hitting
  real /.well-known/databricks-config during resolve().
- testNewWithWorkspaceHost: use FixtureServer URL as workspace host
  instead of https://workspace.cloud.databricks.com.
- Remove unnecessary second fixture from testEndToEndResolveToGetHostType.

Author: tanmay-db

databricks-sdk-java/src/test/java/com/databricks/sdk/core/DatabricksConfigTest.java

@@ -173,22 +173,24 @@ public void testDiscoveryEndpoint() throws IOException {
   }
 
   @Test
-  public void testNewWithWorkspaceHost() {
-    DatabricksConfig config =
-        new DatabricksConfig()
-            .setAuthType("oauth-m2m")
-            .setClientId("my-client-id")
-            .setClientSecret("my-client-secret")
-            .setAccountId("account-id")
-            .setHost("https://account.cloud.databricks.com");
-    String workspaceHost = "https://workspace.cloud.databricks.com";
-
-    DatabricksConfig newWorkspaceConfig = config.newWithWorkspaceHost(workspaceHost).resolve();
-
-    assert newWorkspaceConfig.getHost().equals(workspaceHost);
-    assert newWorkspaceConfig.getAuthType().equals("oauth-m2m");
-    assert newWorkspaceConfig.getClientId().equals("my-client-id");
-    assert newWorkspaceConfig.getClientSecret().equals("my-client-secret");
+  public void testNewWithWorkspaceHost() throws IOException {
+    try (FixtureServer server = new FixtureServer()) {
+      String workspaceHost = server.getUrl();
+      DatabricksConfig config =
+          new DatabricksConfig()
+              .setAuthType("oauth-m2m")
+              .setClientId("my-client-id")
+              .setClientSecret("my-client-secret")
+              .setAccountId("account-id")
+              .setHost("https://account.cloud.databricks.com");
+
+      DatabricksConfig newWorkspaceConfig = config.newWithWorkspaceHost(workspaceHost).resolve();
+
+      assert newWorkspaceConfig.getHost().equals(workspaceHost);
+      assert newWorkspaceConfig.getAuthType().equals("oauth-m2m");
+      assert newWorkspaceConfig.getClientId().equals("my-client-id");
+      assert newWorkspaceConfig.getClientSecret().equals("my-client-secret");
+    }
   }
 
   @Test

databricks-sdk-java/src/test/java/com/databricks/sdk/core/UnifiedHostTest.java

@@ -97,19 +97,21 @@ public void testIsAccountClientForNonAccountsHost() {
   // --- Environment Variable Tests ---
 
   @Test
-  public void testWorkspaceIdFromEnvironmentVariables() {
-    Map<String, String> env = new HashMap<>();
-    env.put("DATABRICKS_HOST", "https://mycompany.databricks.com");
-    env.put("DATABRICKS_WORKSPACE_ID", "987654321");
-    env.put("DATABRICKS_ACCOUNT_ID", "account-abc");
-
-    DatabricksConfig config = new DatabricksConfig();
-    config.resolve(new Environment(env, new ArrayList<>(), System.getProperty("os.name")));
-
-    assertEquals(HostType.WORKSPACE, config.getHostType());
-    assertEquals("987654321", config.getWorkspaceId());
-    assertEquals("account-abc", config.getAccountId());
-    assertEquals(ClientType.WORKSPACE, config.getClientType());
+  public void testWorkspaceIdFromEnvironmentVariables() throws IOException {
+    try (FixtureServer server = new FixtureServer()) {
+      Map<String, String> env = new HashMap<>();
+      env.put("DATABRICKS_HOST", server.getUrl());
+      env.put("DATABRICKS_WORKSPACE_ID", "987654321");
+      env.put("DATABRICKS_ACCOUNT_ID", "account-abc");
+
+      DatabricksConfig config = new DatabricksConfig();
+      config.resolve(new Environment(env, new ArrayList<>(), System.getProperty("os.name")));
+
+      assertEquals(HostType.WORKSPACE, config.getHostType());
+      assertEquals("987654321", config.getWorkspaceId());
+      assertEquals("account-abc", config.getAccountId());
+      assertEquals(ClientType.WORKSPACE, config.getClientType());
+    }
   }
 
   // --- Resolved host type from metadata tests ---
@@ -167,7 +169,6 @@ public void testEndToEndResolveToGetHostType() throws IOException {
             + "\"host_type\":\"unified\"}";
     try (FixtureServer server =
         new FixtureServer()
-            .with("GET", "/.well-known/databricks-config", response, 200)
             .with("GET", "/.well-known/databricks-config", response, 200)) {
       DatabricksConfig config = new DatabricksConfig().setHost(server.getUrl());
       config.resolve(