Panic in the PbGenericBlock()

[bogdanprodanj]

Describe the bug

If I substitute params.BeaconConfig().GenesisForkVersion with params.BeaconConfig().DenebForkVersion in this test

tt.action()
bFunc, ok := BlockMap[bytesutil.ToBytes4(params.BeaconConfig().GenesisForkVersion)]
assert.Equal(t, tt.exists, ok)
if tt.exists {
	b, err := bFunc()
	require.NoError(t, err)
	generic, err := b.PbGenericBlock()
	require.NoError(t, err)
	assert.NotNil(t, generic.GetPhase0())
}

the test will panic on line 128

Has this worked before in a previous version?

Yes, this worked in `v5.0.3`

🔬 Minimal Reproduction

No response

Error

=== RUN   TestInitializeDataMaps
=== RUN   TestInitializeDataMaps/no_change
--- FAIL: TestInitializeDataMaps/no_change (18.89s)

--- FAIL: TestInitializeDataMaps (18.89s)
panic: interface conversion: protoreflect.ProtoMessage is *eth.SignedBeaconBlockDeneb, not *eth.SignedBeaconBlockContentsDeneb [recovered]
	panic: interface conversion: protoreflect.ProtoMessage is *eth.SignedBeaconBlockDeneb, not *eth.SignedBeaconBlockContentsDeneb

goroutine 36 [running]:
testing.tRunner.func1.2({0x100b3fd20, 0x14000418fc0})
	/Users/bogdan/go/pkg/mod/golang.org/[email protected]/src/testing/testing.go:1632 +0x3c0
testing.tRunner.func1()
	/Users/bogdan/go/pkg/mod/golang.org/[email protected]/src/testing/testing.go:1635 +0x57c
panic({0x100b3fd20?, 0x14000418fc0?})
	/Users/bogdan/go/pkg/mod/golang.org/[email protected]/src/runtime/panic.go:785 +0xf0
github.com/prysmaticlabs/prysm/v5/consensus-types/blocks.(*SignedBeaconBlock).PbGenericBlock(0x140002be5b0)
	/Users/bogdan/go/src/github.com/prysmaticlabs/prysm/consensus-types/blocks/getters.go:128 +0x1014
github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/types.TestInitializeDataMaps.func4(0x140002b6d00)
	/Users/bogdan/go/src/github.com/prysmaticlabs/prysm/beacon-chain/p2p/types/object_mapping_test.go:57 +0x228
testing.tRunner(0x140002b6d00, 0x140003ba1e0)
	/Users/bogdan/go/pkg/mod/golang.org/[email protected]/src/testing/testing.go:1690 +0x1a8
created by testing.(*T).Run in goroutine 35
	/Users/bogdan/go/pkg/mod/golang.org/[email protected]/src/testing/testing.go:1743 +0x668

Debugger finished with the exit code 0

### Platform(s)

Mac (Apple Silicon)

### What version of Prysm are you running? (Which release)

v5.2.0

### Anything else relevant (validator index / public key)?

_No response_