Remove unnecessary RecordErrorToSpan process

[goccy]

FYI: Call RecordErrorToSpan here ( https://github.com/mercari/grpc-federation/blob/main/generator/templates/eval.go.tmpl#L129 )

[github-actions]

Code Metrics Report

	main (5b9d3d8)	#232 (d0afe2c)	+/-
Coverage	65.6%	65.6%	0.0%
Code to Test Ratio	1:0.3	1:0.3	+0.0
Test Execution Time	7m1s	7m13s	+12s

Details

  |                     | main (5b9d3d8) | #232 (d0afe2c) | +/-  |
  |---------------------|----------------|----------------|------|
  | Coverage            |          65.6% |          65.6% | 0.0% |
  |   Files             |             71 |             71 |    0 |
  |   Lines             |          11831 |          11831 |    0 |
  |   Covered           |           7756 |           7756 |    0 |
+ | Code to Test Ratio  |          1:0.3 |          1:0.3 | +0.0 |
  |   Code              |          37119 |          37100 |  -19 |
  |   Test              |          12890 |          12890 |    0 |
- | Test Execution Time |           7m1s |          7m13s | +12s |

---

Reported by octocov