Fix linting errors in hero.css

[vtsaplin]

No description provided.

[andreibogdan]

solutions/blocks/hero/hero.css
  35:1  ✖  Unexpected duplicate selector "main .hero .hero-content              no-duplicate-selectors
           .breadcrumb", first used at line 27
 135:1  ✖  Unexpected duplicate selector "main .hero .hero-content", first      no-duplicate-selectors
           used at line 121
 166:1  ✖  Unexpected duplicate selector "main .hero h1", first used at line    no-duplicate-selectors
           152
 177:1  ✖  Expected selector "main .hero h2" to come before selector "main      no-descending-specificity
           .hero.black-background h2"
 178:1  ✖  Expected selector "main .hero h4" to come before selector "main      no-descending-specificity
           .hero.black-background h4"
 440:3  ✖  Unexpected duplicate selector "main .hero  h2", first used at line   no-duplicate-selectors
           431
 469:3  ✖  Unexpected duplicate selector "main .hero .hero-content", first      no-duplicate-selectors
           used at line 462
 483:3  ✖  Unexpected duplicate selector "main .hero .hero-content > div",      no-duplicate-selectors
           first used at line 418
 535:3  ✖  Unexpected duplicate selector "main .hero h2", first used at line    no-duplicate-selectors
           531
 568:3  ✖  Unexpected duplicate selector "main .hero .hero-content", first      no-duplicate-selectors
           used at line 561