fix: use unix timestamps for web serialization #325

Job	Run time
setup	4s
Basic Step	1m 3s
Step with Name	1m 1s
Wait State	1m 1s
Step with Retry	1m 33s
Callback	1m 1s
Run in Child Context	1m 0s
Parallel Operations	57s
Block Example	58s
Steps with Retry	2m 32s
Map Operations	1m 6s
Multiple Wait	51s
Wait for Condition	1m 0s
Map with Min Successful	57s
Simple Execution	1m 0s
Logger Example	1m 1s
Parallel with Max Concurrency	1m 7s
Map with Failure Tolerance	1m 23s
Map with Max Concurrency	1m 5s
Run in Child Context Large Data	57s
Parallel with Wait	56s
Parallel with Custom SerDes	1m 2s
Parallel with Failure Tolerance	59s
Map with Custom SerDes	1m 4s
Map with Batch SerDes	1m 7s
Hello World	1m 1s
Parallel with Batch SerDes	1m 0s
	28m 46s

Provide feedback