test(s2n-quic-core): Enable Kani on more Bolero harnesses

[qinheping]

Resolved issues:

N/A

Description of changes:

Enable Kani on a few Bolero harnesses (try_fit_test and fuzz_builder). This brings up the number of harnesses run by Kani from 32 to 34.

The runtime doesn't change much on my local machine. Current:

Complete - 32 successfully verified harnesses, 0 failures, 32 total.
	Command being timed: "cargo kani --tests"
	User time (seconds): 2075.21
	System time (seconds): 43.13
	Percent of CPU this job got: 100%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 34:59.25
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 2261392
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 14352
	Minor (reclaiming a frame) page faults: 14704137
	Voluntary context switches: 69401
	Involuntary context switches: 340621
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 1
	Page size (bytes): 4096
	Exit status: 0

After:

Complete - 34 successfully verified harnesses, 0 failures, 34 total.
	Command being timed: “cargo kani --tests”
	User time (seconds): 2108.20
	System time (seconds): 47.74
	Percent of CPU this job got: 100%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 35:36.26
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 2285648
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 57776
	Minor (reclaiming a frame) page faults: 15529304
	Voluntary context switches: 71173
	Involuntary context switches: 106178
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 1
	Page size (bytes): 4096
	Exit status: 0

Call-outs:

Testing:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.