fix(rp): do not fetch bundled framework libraries from registry

[zackees]

Problem\n\nArduino-Pico bundles libraries such as BTstackLib and HTTPUpdate under libraries/. The RP orchestrator correctly passes lib_deps declarations to framework LDF, which selects those bundled sources, but then passes the same declarations to the generic external-library installer.\n\nA clean RP2350W AutoResearch build with Arduino-Pico 5.7.0 therefore stops before compilation:\n\n\nbuild error: package error: library 'BTstackLib' not found in registry\n\n\nThe library is present at /libraries/BTstackLib; it must not be fetched from the registry.\n\n## Reproduction\n\n1. Select RP2350W with Arduino-Pico 5.7.0.\n2. Set lib_deps = BTstackLib, HTTPUpdate.\n3. Run a clean fbuild deploy/build.\n4. Observe the registry lookup failure for the bundled library.\n\n## Expected\n\n- declarations matching bundled framework library directory names select those framework sources;\n- matching declarations are removed from the external installer input;\n- URL/path/registry-only declarations remain external;\n- matching is case-insensitive and preserves existing owner/version normalization;\n- focused tests and an RP2350W build pass.\n\n## Context\n\nDiscovered while validating #1301 for FastLED/FastLED#3899. Coordinated with FastLED/FastLED#3899.