Fix spelling errors in comments, docstrings, and UI widget names

[mr-raj12]

Fix spelling errors in comments, docstrings, and UI widget names

Description

This PR fixes several spelling errors identified using codespell across the codebase:

File	Line	Typo	Fix
src/vorta/profile_export.py	103	incase	in case
src/vorta/borg/info_archive.py	49	incase	in case
src/vorta/views/archive_tab.py	1048	everytime	every time
src/vorta/views/partials/treemodel.py	415	wont	won't
src/vorta/views/partials/treemodel.py	565	posess	possess
src/vorta/assets/UI/about_tab.ui	121, 226	seperator (widget name)	separator

Related Issue

Fixes #2371

Motivation and Context

Clean up spelling errors to improve code readability and maintain code quality. The seperator fix in about_tab.ui is a widget name attribute that is not referenced anywhere in Python code, so renaming is safe.

How Has This Been Tested?

• All pre-commit checks pass (ruff, ruff-format, trailing whitespace, etc.)
• Changes are limited to comments, docstrings, and an unreferenced UI widget name, so no functional testing is required

Screenshots (if appropriate):

N/A - No visual changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have read the CONTRIBUTING guide.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

I provide my contribution under the terms of the license of this repository and I affirm the Developer Certificate of Origin.

[mr-raj12]

@m3nu I have raised the PR solving the issue #2371 related to typos.