The fix for #8241 set FileRequestIntent=Backup on
service.ClientOptions so the azfile SDK emits the
x-ms-file-request-intent header was inadvertently dropped in this
commit (released in v1.73.0)
846f193806 azureblob,azurefiles: factor the common auth into a library
This broke azurefiles with OAuth (service principal secret,
certificate, MSI, etc.) with:
400 MissingRequiredHeader: x-ms-file-request-intent
This restores it in the azurefiles SetClientOptions callback. The SDK
only emits the header for TokenCredential auth, so shared-key and SAS
paths are unaffected.
90028ab3da