[ENH] Changed the favicon to neurobagel logo

[rmanaem]

• Closes Add neurobagel logo #221

Checklist

• PR has an interpretable title with a prefix ([ENH], [FIX], [REF], [TST], [CI], [MNT], [INF], [MODEL], [DOC]) (see https://neurobagel.org/contributing/pull_requests for more info)
• PR links to GitHub issue with mention Closes #XXXX
• Tests pass
• Checks pass

For new features:

• Tests have been added

For bug fixes:

• There is at least one test that would fail under the original bug conditions.

[coveralls]

Pull Request Test Coverage Report for Build 6867790297

• 10 of 11 (90.91%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.1%) to 99.713%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
app/main.py	10	11	90.91%

Totals
Change from base Build 6856558278:	-0.1%
Covered Lines:	695
Relevant Lines:	697

---

💛 - Coveralls

[alyssadai]

Cool PR @rmanaem!

One question about the logo file location, otherwise 🧑‍🍳!

🍒: I'd consider the [MNT] prefix for this PR, but will leave the final decision to you.

[rmanaem]

I'd consider the [MNT] prefix for this PR, but will leave the final decision to you.

i believe we used [ENH] in query tool and annotation tool so I'll use [ENH] to stay consistent.