Add throttling to contact api endpoint #1250

Job	Run time
Test dev setup on ubuntu-latest	41s
Build python wheel	1m 16s
Test dev setup on windows-latest	3m 6s
Test dev setup on macos-latest	39s
lint / Lint	39s
Test installation of all dependencies	49s
End-to-end Test (Python: 3.12, DB: postgres)	7m 35s
Test (Python: 3.8, DB: mysql)	27m 41s
Test (Python: 3.8, DB: postgres)	27m 24s
Test (Python: 3.12, DB: mysql)	27m 48s
Test (Python: 3.12, DB: postgres)	27m 42s
Indicate completion to coveralls	2s
required-checks-pass	2s
	2h 5m 24s

Provide feedback