(Some) runtime calls truncate the first 2 bytes

[DragonDev1906]

Tested on the Polkadot/Ajuna parachain and Polkadot

• metadata.metadata() returns: 0x6d6574610ea10a000c1c
• metadata.metadataAtVersion(15) returns 0x74610f250b000c1c

According to the specs the metadata starts with ascii "meta": 6d657461, followed by the version (0x0f or 0x0e)

In the first one it's not easy to notice, but 0x6d65 is not the length of the returned data (as it should be according to the type).
The second one is far easier to see, as it starts with ascii ta followed by the 0x0f version byte.

I have run the runtime code in a different environment, where it matches the Option<Vec<u8>> type and the data itself starts with "meta", which leads me to believe the first two bytes are truncated by the frontend or perhaps the node/backend.