Update go version in the go.mod

[genkiroid]

go mod tidy -go=1.20

[github-actions]

Code Metrics Report

	main (506f03c)	#26 (32906e5)	+/-
Coverage	75.0%	75.0%	0.0%
Code to Test Ratio	1:0.9	1:0.9	0.0
Test Execution Time	5s	20s	+15s

Details

  |                     | main (506f03c) | #26 (32906e5) | +/-  |
  |---------------------|----------------|---------------|------|
  | Coverage            |          75.0% |         75.0% | 0.0% |
  |   Files             |              1 |             1 |    0 |
  |   Lines             |            100 |           100 |    0 |
  |   Covered           |             75 |            75 |    0 |
  | Code to Test Ratio  |          1:0.9 |         1:0.9 |  0.0 |
  |   Code              |            315 |           315 |    0 |
  |   Test              |            280 |           280 |    0 |
- | Test Execution Time |             5s |           20s | +15s |

---

Reported by octocov