[lab] Add missing clsx calls

[merceyz]

• I have followed (at least) the PR section of the contributing guide.

Added two missing clsx calls, without them the clsx calls using the objects later all have to go over the object, wasting resources.

[mui-pr-bot]

Details of bundle changes.

Comparing: 89687f3...32774d8

bundle	parsed diff	gzip diff	prev parsed	current parsed	prev gzip	current gzip
@material-ui/core	0.00%	-0.00%	315,938	315,938	86,589	86,585
@material-ui/core/Paper	0.00%	+0.01% 🔺	67,870	67,870	20,155	20,158
@material-ui/core/Paper.esm	0.00%	-0.03%	61,152	61,152	18,952	18,947
@material-ui/core/Popper	0.00%	+0.01% 🔺	28,740	28,740	10,351	10,352
@material-ui/core/Textarea	0.00%	-0.17%	5,513	5,513	2,382	2,378
@material-ui/core/TrapFocus	0.00%	-0.06%	3,744	3,744	1,581	1,580
@material-ui/core/styles/createMuiTheme	0.00%	0.00%	15,960	15,960	5,782	5,782
@material-ui/core/useMediaQuery	0.00%	0.00%	2,106	2,106	975	975
@material-ui/lab	-0.05%	-0.17%	139,135	139,068	42,835	42,763
@material-ui/styles	0.00%	0.00%	51,353	51,353	15,176	15,176
@material-ui/system	0.00%	+0.14% 🔺	14,458	14,458	4,178	4,184
Button	0.00%	-0.02%	84,061	84,061	25,588	25,582
Modal	0.00%	-0.01%	20,344	20,344	6,685	6,684
colorManipulator	0.00%	0.00%	3,904	3,904	1,543	1,543
docs.landing	0.00%	0.00%	56,054	56,054	13,943	13,943
docs.main	0.00%	0.00%	645,766	645,766	203,099	203,099
packages/material-ui/build/umd/material-ui.production.min.js	0.00%	0.00%	294,878	294,878	84,097	84,097

Generated by 🚫 dangerJS against 32774d8

[joshwooding]

Thanks 👍