Create assets folder if it is missing when writing Report #19088

Description:

We are receiving errors such as:

• Scheduler: Error Unable to create output file
• Scheduler: Error ReportRenderer: Could not write to file

This appears to happen when the assets directory doesn't exist in the tmp folder when the Scheduled reports task is run via ./console core:run-scheduled-task. This has been observed for pdf and csv.

It appears you can recreate this as such:

• Create a report that can be generated
• breakpoint if ($shouldExecuteTask) in Scheduler.php
• Set $shouldExecuteTask to true.
• if tmp/assets is missing at \Piwik\ReportRenderer::writeFile then the error will occur. This will also occur at $this->Error('Unable to create output file: '.$name); in tcpdf

Review

• [ ] Functional review done
• [ ] Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done
• [ ] Wording review done
• [ ] Code review done
• [ ] Tests were added if useful/possible
• [ ] Reviewed for breaking changes
• [ ] Developer changelog updated if needed
• [ ] Documentation added if needed
• [ ] Existing documentation updated if needed