Update GraphicsMagick to 1.3.36

Why does this need?

[...] This release is the product of significant bug and security fixes due to GraphicsMagick participating in Google's oss-fuzz project. This release fixes a number of issues detected by oss-fuzz (11 issues remain open) as well as a number of issues reported via the SourceForge bug tracker, or discovered via testing.

Part of &2724

cf. !269 (merged)