zink: do not require VK_KHR_external_memory

This is only required for the DRI-path. For the swrast code-path, we
don't need this.

We also don't need to explicitly test for it in the DRI-path, because we
test for KHR_external_memory_fd, which depends on KHR_external_memory. So
no implementation will expose the former without the latter.

Fixes: f1432fd3e2d ("zink: generate extension infrastructure using a python script")
Reviewed-by: Hoe Hao Cheng <haochengho12907@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7882>
(cherry picked from commit 59a6705ccef1f8a7b1e7f6486e33603c6d6b7606)
diff --git a/.pick_status.json b/.pick_status.json
index dcaa8c0..0274e40 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -121,7 +121,7 @@
         "description": "zink: do not require VK_KHR_external_memory",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": "f1432fd3e2d915f09a295f1ffb878471ce4e4d73"
     },
diff --git a/src/gallium/drivers/zink/zink_device_info.py b/src/gallium/drivers/zink/zink_device_info.py
index 149a5bf..d4082f9 100644
--- a/src/gallium/drivers/zink/zink_device_info.py
+++ b/src/gallium/drivers/zink/zink_device_info.py
@@ -58,7 +58,7 @@
 def EXTENSIONS():
     return [
         Extension("VK_KHR_maintenance1",             required=True),
-        Extension("VK_KHR_external_memory",          required=True),
+        Extension("VK_KHR_external_memory"),
         Extension("VK_KHR_external_memory_fd"),
         Extension("VK_KHR_vulkan_memory_model"),
         Extension("VK_EXT_conditional_rendering",    alias="cond_render", have_feature="conditionalRendering"),