presignUrl with write permissions and BYO credentials fail on PUT Blob

### Expected Behaviour
write permissions should allow to send a PUT request to the presignURL even with BYO credentials

### Actual Behaviour
This is failing for BYO credentials:
- `const files = await Files.init({ azure: {mycreds} })`
- `const url = await files.generatePresignURL('hello.txt', { expiryInSeconds: 500, permissions: 'w' })`
- `await fetch(url, { method: 'PUT', body: 'hello23' })` => returns 400 missing header (seems that it wants the Authorization header)

same works fine with TVM credentials

### Reproduce Scenario (including but not limited to)

#### Steps to Reproduce

#### Platform and Version

#### Sample Code that illustrates the problem

#### Logs taken while reproducing problem

Start with Files.init and generatePresignURL, then run the reported BYO-credentials reproduction using fetch with PUT and the hello23 body. Compare it with the working TVM-credentials case; done means a URL generated with write permissions accepts the PUT without requiring an Authorization header.

Written by the indexing model from the issue text.