### Issue
PDF reports fail when attachments are remote URLs or cloud storage resources. The `to_pdf_stream()` method expects local file data but receives boolean values from remote attachments, causing a TypeError.

### Solution
Download remote resources before processing them in PDF reports. This ensures all attachments have accessible data regardless of storage type.

### Affected Reports
- `account.report_original_vendor_bill` - Vendor bill reports
- `hr_expense.report_expense_sheet` - Expense sheet reports

### Affected Versions
- 18.0+ (17.0 theoretical; cloud_storage wasn't implemented, so doesn't make sense)

### Reproduction Steps

#### Option A: HR Expense Report
1. Create HR expense record
2. Add attachment with type=url/cloud_storage pointing to valid PDF URL
3. Link attachment to hr.expense record
4. Generate expense report → TypeError occurs

#### Option B: Vendor Bill Report
1. Create vendor bill (account.move)
2. Add attachment with type=url/cloud_storage pointing to valid PDF URL
3. Link attachment to account.move record
4. Print Original Vendor Bill → TypeError occurs

### Error Details
```python
TypeError: a bytes-like object is required, not 'bool'
  at /odoo/tools/pdf/__init__.py:220 in to_pdf_stream
  from /odoo/addons/hr_expense/models/ir_actions_report.py:29
```

#### Reference
Client demo: https://drive.google.com/file/d/1HUvZqZ21NiX34T2IQhuVNbLP41xSV7jq/view

OPW-5036638

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Forward-Port-Of: odoo/odoo#227571
Forward-Port-Of: odoo/odoo#226094

Versions
--------
- 16.0+

Steps
-----
1. Have 2 eCommerce sites;
2. have a user with an open cart in both sites;
3. have a reward applied in one or both of carts;
4. have a fiscal position applicable to the user's address;
5. change the user's country to one with a different fiscal position.

Issue
-----
> ValueError: Expected singleton: sale.order(1, 2)

Cause
-----
As of commit ede8846987a98, fiscal positions get recomputed on address changes. When a fiscal position changes, the `_recompute_prices` method gets called on all open carts.

This method does not include an `ensure_one` check, so it should be able to handle multiple sales orders.

However, the `sale_loyalty` override will call `_update_programs_and_rewards` on `self` if any reward line is encountered. This method does have an `ensure_one` check, leading to the error.

Solution
--------
Rewrite the override as a loop, so it can handle multiple records in `self`.

opw-5017669

Forward-Port-Of: odoo/odoo#224225

Currently an error occurs when creating the attendee records.

Steps to Reproduce:

 - Install the `website_slide` module.
 - Go to `Reporting` > `Attendees`.
 - Go to either the `Graph or Pivot View` and click on any `count` value.
 - Open any attendee record and click on `New`.

`SyntaxError: syntax error at or near ")"
LINE 18: WHERE SCP.id IN ()
^`

This error occurs when creating an Attendee record. The _compute_next_slide_id
method runs every time the record is accessed, which causes the error [1].
As clearly mentioned in [this commit](https://github.com/odoo/odoo/commit/fd2fb88bb155b680147313433d22a2b7388c902c#diff-1ee3fce434db0c4e897973eebf5c1be501196cbd413e6c250ecc973238f939b9L292-R326), when a compute method is declared
without the @api.depends(...) decorator or with no actual dependencies,
the computed field will still be initialized when creating a new record
from a form view.

This commit ensures that when the compute method runs and the record
has not been created yet, the next_slide_id is set to False.

[1]:- https://github.com/odoo/odoo/blob/9f18013bc05e6657f5d41c05931fcdafad827d54/addons/website_slides/models/slide_channel.py#L91

sentry-6465821899

---
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Forward-Port-Of: odoo/odoo#217104