Fix relnotes

Author: flying-sheep

docs/release-notes/1.12.1.md

@@ -8,6 +8,7 @@
 #### Bug fixes
 
 - Prevent segfault when running {func}`scanpy.pp.highly_variable_genes` with `flavor='seurat_v3{,_paper}'` and some all-zero genes {smaller}`P Angerer` ({pr}`3980`)
+- Clarify and deduplicate shared parameter documentation between {func}`scanpy.tl.leiden` and {func}`scanpy.tl.louvain` {smaller}`Abi` ({pr}`3986`)
 - {func}`scanpy.pp.combat` now raises a {class}`ValueError` when a batch contains fewer than 2 cells, instead of silently producing NaN values in the corrected data {smaller}`L Zhang` ({pr}`3994`)
 - Fix crashes when running numba in dask by using the threadsafe {func}`fast_array_utils.numba.njit` {smaller}`P Angerer` ({pr}`4015`)
 - {func}`scanpy.tl.umap` no longer silently mutates `adata.obsp['connectivities']` via a shared sparse buffer {smaller}`N Justice` ({pr}`4031`)