refactor: remove deprecated Sass wrapper macros

[cdavalos7]

Motivation for features / changes

Unblock internal LSC intended to remove workarounds for Sass and bad practices. Internal issue: b/508363660. This PR removes the wrappers for Sass build rules. Sass rules must directly declare their dependencies.

Per Sass build rules guidelines, wrapper macros are discouraged, and tf_external_sass_libray was relying on a loophole (passing a sass_library to another sass_library's srcs) that is being closed.

Technical description of changes

• Replace tf_sass_binary,tf_sass_library, and tf_external_sass_libray wrappers with direct calls to sass_binary, sass_library, and npm_sass_library from @io_bazel_rules_sass.
• Updated hash version rules_sass from 1.55.0 to 1.69.5
• Replaces the angular_material_sass_deps target with a direct npm_sass_library call. This produces a SassInfo provider consumed via deps, complying with the rule that sass libraries must declare deps directly rather than passing one library to another's srcs.
• Added include_paths = ["external/npm/node_modules"] to each sass_binary so dart-sass can resolve @use '@angular/material'. The old wrapper set this automatically, now it has to be set per target.

Detailed steps to verify changes work correctly (as executed by you)

• BUILD
• Standalone running
• No console errors