feat: prevent yield calculation for ## as ingredient headline

[j0hannesr0th]

Topic and Scope

fixes #1985

2023-12-15_130713.mp4

Concerns/issues

none.

Formal requirements

There are some formal requirements that should be satisfied. Please mark those by checking the corresponding box.

• I did check that the app can still be opened and does not throw any browser logs
• I created tests for newly added PHP code (check this if no PHP changes were made)
• I updated the OpenAPI specs and added an entry to the API changelog (check if API was not modified)
• I notified the matrix channel if I introduced an API change

[github-actions]

Test Results

     12 files     572 suites   1m 31s ⏱️
   552 tests    552 ✔️ 0 💤 0 ❌
2 208 runs  2 207 ✔️ 1 💤 0 ❌

Results for commit 8d4a606.

[christianlupus]

LGTM