[Bug]: mimetype inconsistency between `Detection.detectPath` and `Loader.updateFilecache`

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• Nextcloud Server is running on 64bit capable CPU, PHP and OS.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

For files named like .ext e.g. ".gpx", ".ext" or ".maps" get different mimetypes by

https://github.com/nextcloud/server/blob/ce1dddcc642f8de6887a48e778942969b8223d57/lib/private/Files/Type/Detection.php#L195
or
https://github.com/nextcloud/server/blob/ce1dddcc642f8de6887a48e778942969b8223d57/lib/private/Files/Type/Loader.php#L164.

To clearify its about files which start with a . and then just have the extension.
Therefore existing files get different mime-types then new file.

Steps to reproduce

1. Create ".ext" file
2. Run Loader->updateFilecache("ext", mimeTypeId)
3. Create corresponding Mimetype mapping
4. Uploade a file called ".ext" to a different folder
5. See that it gets a different Mimetype

Expected behavior

• Get the same Mimetype
• It would be nice if it would be the Mimetype in the mapping, then mimetypes can be used to find .noindex and .nomedia files, or in maps a .maps file. Searching the file over the mimetype is faster as there is a db index.

Installation method

None

Operating system

None

PHP engine version

None

Web server

None

Database engine version

MySQL

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

[]

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

Start with lib/private/Files/Type/Detection.php near line 195 and lib/private/Files/Type/Loader.php near line 164, comparing how names such as .ext are handled. Reproduce the listed file-cache and upload steps, then verify that both paths assign the mimetype from the corresponding mapping consistently.