Make msvc_env_cmd no-op for arm64 (#4867)

Co-authored-by: Isuru Fernando <[email protected]>

conda_build/windows.py

@@ -110,6 +110,9 @@ def msvc_env_cmd(bits, config, override=None):
         "If this recipe does not use a compiler, this message is safe to ignore.  "
         "Otherwise, use {{compiler('<language>')}} jinja2 in requirements/build."
     )
+    if bits not in ["64", "32"]:
+        log.warn(f"The legacy MSVC compiler setup does not support {bits} builds. ")
+        return ""
     if override:
         log.warn(
             "msvc_compiler key in meta.yaml is deprecated. Use the new"

news/4867-arm64-msvc-env-cmd-no-op

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* Added a check to print an additional warning and return an empty string when bits is "arm64" in msvc_env_cmd. (#4867)