build(deps): bump bootstrap from 4.6.2 to 5.3.1 in /web/ui #194

Job	Run time
UI tests	2m 40s
Go tests	2m 40s
Go tests with previous Go version	1m 47s
golangci-lint	7m 36s
Mixins tests	3m 33s
Build Prometheus for common architectures (0)	3m 33s
Build Prometheus for common architectures (1)	3m 17s
Build Prometheus for common architectures (2)	3m 33s
Go tests on Windows	10m 15s
Build Prometheus for all architectures	0s
codeql / Analyze (go)	12m 24s
codeql / Analyze (javascript)	2m 59s
fuzzing / Fuzzing	2m 34s
Publish release arfefacts	0s
Publish UI on npm Registry	0s
Publish main branch artifacts	0s
	56m 51s

Provide feedback