add friction model "Hofer" #1625

Job	Run time
Sphinx docs check	32s
Tests (3.9, ubuntu-latest)	41s
Linting	18s
Tests (3.9, windows-latest)	1m 18s
Tutorial tests (3.9, ubuntu-latest)	1m 20s
Tests (3.10, ubuntu-latest)	45s
Tutorial tests (3.9, windows-latest)	2m 23s
Tests (3.10, windows-latest)	1m 35s
Tutorial tests (3.10, ubuntu-latest)	1m 14s
Tutorial tests (3.10, windows-latest)	2m 7s
Tests (3.11, ubuntu-latest)	55s
Tutorial tests (3.11, ubuntu-latest)	1m 36s
Tests (3.11, windows-latest)	1m 48s
Tutorial tests (3.11, windows-latest)	2m 40s
Tests (3.12, ubuntu-latest)	42s
Tutorial tests (3.12, ubuntu-latest)	1m 12s
Tests (3.12, windows-latest)	1m 11s
Tutorial tests (3.12, windows-latest)	2m 8s
	24m 25s

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