MCP Inspector v2.8.0 released: fixes /api authentication bypass and adds key file configuration

MCP Inspector released v2.8.0, fixing a previous issue where setting DANGEROUSLY_OMIT_AUTH to values other than true/1 could also affect /api authentication; now only true/1 disables that authentication. The release also adds the MCP_INSPECTOR_SECRET_KEY_FILE configuration option and key storage documentation for each runtime, adds a security advisory skill, adds the Mcp-Method marker to modern notification POSTs, and adjusts the request body release logic for the OIDC compatibility path.