Revert "apierr: Alias ErrResourceAlreadyExists to ErrAlreadyExists" (#1658)

Reverts #1639

Author: simonfaltum

NEXT_CHANGELOG.md

@@ -8,8 +8,6 @@
 
 ### Bug Fixes
 
- * Alias `apierr.ErrResourceAlreadyExists` to `apierr.ErrAlreadyExists` so `errors.Is` matches both the gRPC-canonical `ALREADY_EXISTS` and the Databricks-specific `RESOURCE_ALREADY_EXISTS` error codes, regardless of which one the backend returns.
-
 ### Documentation
 
 ### Internal Changes

apierr/error_mapping.go

@@ -17,11 +17,7 @@ var testTable = []mapping{
 	codeMapping(409, "ABORTED", ErrAborted),
 	codeMapping(409, "ABORTED", ErrResourceConflict),
 	codeMapping(409, "ALREADY_EXISTS", ErrAlreadyExists),
-	codeMapping(409, "ALREADY_EXISTS", ErrResourceAlreadyExists),
 	codeMapping(409, "ALREADY_EXISTS", ErrResourceConflict),
-	codeMapping(409, "RESOURCE_ALREADY_EXISTS", ErrAlreadyExists),
-	codeMapping(409, "RESOURCE_ALREADY_EXISTS", ErrResourceAlreadyExists),
-	codeMapping(409, "RESOURCE_ALREADY_EXISTS", ErrResourceConflict),
 	statusMapping(429, ErrTooManyRequests),
 	codeMapping(429, "REQUEST_LIMIT_EXCEEDED", ErrTooManyRequests),
 	codeMapping(429, "REQUEST_LIMIT_EXCEEDED", ErrRequestLimitExceeded),