Solve models in parallel with multi processing #561

Job	Run time
Lint	36s
Tests (3.10, git+https://github.com/pastas/[email protected])	1m 42s
Tests (3.10, git+https://github.com/pastas/[email protected])	1m 49s
Tests (3.10, git+https://github.com/pastas/[email protected])	1m 39s
Tests (3.10, git+https://github.com/pastas/[email protected])	1m 53s
Tests (3.10, git+https://github.com/pastas/pastas.git@dev)	1m 39s
Tests (3.11, git+https://github.com/pastas/[email protected])	1m 40s
Tests (3.11, git+https://github.com/pastas/[email protected])	1m 34s
Tests (3.11, git+https://github.com/pastas/[email protected])	1m 55s
Tests (3.11, git+https://github.com/pastas/[email protected])	1m 44s
Tests (3.11, git+https://github.com/pastas/pastas.git@dev)	2m 48s
Tests (3.12, git+https://github.com/pastas/[email protected])	1m 32s
Tests (3.12, git+https://github.com/pastas/pastas.git@dev)	1m 37s
	22m 8s

Provide feedback