Simplify parameter matcher for hashes

[nitishr]

Improves the handling of keyword and positional hash argument matching. Simplifies the logic around matching keyword and positional hashes, removes redundant code, and ensures that the behavior aligns with Ruby's keyword argument handling.

Key Changes:

1. Simplified to_matcher Method:

   • Removed the last parameter from the to_matcher method in instance_methods.rb. This simplifies the logic and removes unnecessary complexity in determining whether a matcher is the last in a sequence.

2. Refactored PositionalOrKeywordHash Class:

   • Removed the last_expected_value parameter and related logic from the PositionalOrKeywordHash class. The class now focuses on matching hash entries exactly and handling keyword arguments more straightforwardly.
   • Simplified the matches? method to handle both positional and keyword hashes without needing to check if the matcher is the last one.
   • Removed redundant methods like matches_last_actual_value? and last_expected_value_is_positional_hash?.

3. Updated Tests:

   • Removed or updated tests that were checking behavior related to the last parameter, as it is no longer relevant.
   • Simplified test cases to focus on the core functionality of matching keyword and positional hashes.
   • Updated the strict_keyword_argument_matching_test.rb to reflect the new behavior, ensuring that positional and keyword arguments are matched correctly.

[nitishr]

@floehopper I started some comprehension refactoring in order to investigating #594 and #734. In the process, I noticed a number of opportunities for simplification, and the PR is the result.