Not to be installed to an environment that has a Grid Infrastructure home
Patch 39036936 is 19c Grid Release Update 19.31 for Linux x64:
Patch 39036936 - GI Release Update 19.31.0.0.260421
This Grid RU patch states it contains the Database RU patch:
"Table 1-2 Patch Numbers Installed as Part of this Bundle Patch
Patch Number Description Applicable Homes
39034528
Database Release Update 19.31.0.0.260421
Only Oracle home for non-Oracle RAC setup. Both Oracle home and Grid home for Oracle RAC setup.
<more patches follow this list>"
It confirms this patch to be installed in the Oracle Home, and in the Grid Oracle Home.
So, now look at the Readme of the Database RU (in p39036936_190000_Linux-x86-64.zip\39036936\39034528)
It says, this is patch :