Use YAML.load instead of YAML.load_file.

YAML::load is about the same performance as YAML.load.

But YAML.load is 1-char shorter. :sunglasses:

Calculating -------------------------------------
      YAML.load_file       330 i/100ms
          YAML::load       415 i/100ms
           YAML.load       412 i/100ms
-------------------------------------------------
      YAML.load_file     3518.6 (±22.2%) i/s -      16830 in   5.066625s
          YAML::load     4177.7 (±7.9%) i/s -      20750 in   5.002723s
           YAML.load     4168.8 (±7.9%) i/s -      21012 in   5.078871s

Comparison:
          YAML::load:     4177.7 i/s
           YAML.load:     4168.8 i/s - 1.00x slower
      YAML.load_file:     3518.6 i/s - 1.19x slower