eth2wrap: initialize fork version on lazy

[gsora]

Instead of relying on the lazy interface to set the Eth2CL fork version, initialize it immediately before returning it as a lazy.

Fixes exits through VCs.

category: bug ticket: none

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 20.75472% with 42 lines in your changes missing coverage. Please review.

Project coverage is 56.82%. Comparing base (f286523) to head (79c0acb). Report is 2 commits behind head on main.

Files	Patch %	Lines
cluster/manifestpb/v1/manifest.pb.go	0.00%	9 Missing :warning:
dkg/dkgpb/v1/frost.pb.go	0.00%	7 Missing :warning:
core/corepb/v1/consensus.pb.go	0.00%	5 Missing :warning:
core/corepb/v1/priority.pb.go	0.00%	5 Missing :warning:
core/corepb/v1/core.pb.go	0.00%	4 Missing :warning:
app/log/loki/lokipb/v1/loki.pb.go	0.00%	3 Missing :warning:
dkg/dkgpb/v1/bcast.pb.go	0.00%	3 Missing :warning:
dkg/dkgpb/v1/sync.pb.go	0.00%	2 Missing :warning:
app/app.go	0.00%	1 Missing :warning:
app/peerinfo/peerinfopb/v1/peerinfo.pb.go	50.00%	1 Missing :warning:
... and 2 more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #3131 +/- ## ========================================== + Coverage 56.73% 56.82% +0.09% ========================================== Files 208 208 Lines 29308 29314 +6 ========================================== + Hits 16628 16658 +30 + Misses 10838 10817 -21 + Partials 1842 1839 -3 ```

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[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud