[TimePicker] Add missing themeAugmentation entry

[LukasTy]

Fix #7730

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	509.7	900.4	797.7	707.12	164.484
Sort 100k rows	ms	623.7	1,068	766	881.72	162.659
Select 100k rows	ms	206	287.7	227.8	237.06	27.717
Deselect 100k rows	ms	152.7	205.3	164.2	175.7	23.182

Generated by 🚫 dangerJS against 42ff436

[alexfauquette]

I'm wondering if it would not be easier to automate the generation of those files

[LukasTy]

I'm wondering if it would not be easier to automate the generation of those files

Yup, I believe we could look into that. 🙈
I was looking into coming up with a type, which would enforce themeAugmentation.spec to contain all the components from props file, but that is tedious to do and could still allow for human error 🤔

[LukasTy]

Ended up with a different approach (#7808) preventing the ability to introduce errors in d.ts files.