[MCP] Allow MCP sdk 0.7

[jbtronics]

Q	A
Branch?	main
Tickets
License	MIT
Doc PR

Allow MCP SDK 0.7 for compatibility with latest symfony/mcp-bundle release

[soyuka]

Thanks @jbtronics — picking this up in #8425, which keeps your src/Mcp constraint change and adds the two pieces needed to actually get CI green:

• the root composer.json still pins mcp/sdk: ^0.6, so composer install stays unresolvable against symfony/mcp-bundle (that is why the checks here are all red);
• symfony/mcp-bundle is pinned to ^0.12 instead of dev-main so an upstream main release cannot break the build again;
• McpController gained a required MiddlewareFactory argument in v0.12.0, which the Laravel provider now passes — this also fixes the 10 McpTest failures the Laravel jobs have been carrying since mid-July.

It is opened against 4.3 rather than main since all three branches are affected and the fix should flow up. Closing in favour of that one.