Serialize r-tree index scan and plan #181

Job	Run time
Build extension binaries / Generate matrix	26s
Build extension binaries / Linux (linux_amd64, ubuntu:18.04, x64-linux)	12m 23s
Build extension binaries / DuckDB-Wasm (wasm_mvp, wasm32-emscripten)	41m 14s
Build extension binaries / Linux (linux_amd64_gcc4, quay.io/pypa/manylinux2014_x86_64, x64-linux)	13m 58s
Build extension binaries / MacOS (osx_amd64, x86_64, x64-osx)	10m 37s
Build extension binaries / DuckDB-Wasm (wasm_eh, wasm32-emscripten)	42m 22s
Build extension binaries / Linux (linux_arm64, ubuntu:18.04, arm64-linux)	14m 25s
Build extension binaries / Windows (windows_amd64, x64-windows-static-md)	57m 11s
Build extension binaries / MacOS (osx_arm64, arm64, arm64-osx)	7m 51s
Build extension binaries / DuckDB-Wasm (wasm_threads, wasm32-emscripten)	40m 46s
Build extension binaries / Windows (windows_amd64_rtools, x64-mingw-static)	1h 22m 31s
Deploy extension binaries	0s
	5h 23m 44s

Provide feedback