fix(api-reference): correct duplicate l2LegacySharedBridge key in BridgeContractsResponse

[memosr]

The BridgeContractsResponse schema in api-reference/openapi.json defines l2LegacySharedBridge twice, which makes the file invalid.

Impact

Running mint dev on a clean clone fails to load the OpenAPI tab entirely:

erro Openapi file api-reference/openapi.json defined in tab in your docs.json exists but
     is invalid: Invalid JSON or YAML syntax: duplicated mapping key (6190:13)

Root cause

The second entry was meant to be l2SharedDefaultBridge. Its own description already said "L2 Shared default bridge address", so this looks like a copy/paste slip when the field was added.

Verification

Checked against the live mainnet RPC (zks_getBridgeContracts on https://api.mainnet.abs.xyz):

{
  "l1Erc20DefaultBridge": "0x57891966931eb4bb6fb81430e6ce0a03aabde063",
  "l1SharedDefaultBridge": "0x8829ad80e425c646dab305381ff105169feece56",
  "l1WethBridge": "0x0000000000000000000000000000000000000000",
  "l2Erc20DefaultBridge": "0x0000000000000000000000000000000000010003",
  "l2LegacySharedBridge": "0x954ba8223a6bfec1cc3867139243a02ba0bc66e4",
  "l2SharedDefaultBridge": "0x0000000000000000000000000000000000010003",
  "l2WethBridge": "0x0000000000000000000000000000000000000000"
}

Changes

• Renamed the duplicated l2LegacySharedBridge to l2SharedDefaultBridge
• Corrected its example to 0x0000000000000000000000000000000000010003
• Corrected the l2Erc20DefaultBridge example, which was 0x0...0000 instead of the actual 0x0...010003

The endpoint-level example at openapi.json:4520 was already correct, which is likely why this went unnoticed. Only the x-definitions schema was affected.

After

mint dev starts without the parse error and the OpenAPI tab loads. No .mdx file references zks_getBridgeContracts examples, so no other files needed changes.