How to tell Gulp to skip or ignore some files in gulp.src([…])?

Add a !:

gulp.task('styles', function() {
  gulp.src([
      '!css/ignnore.css', // <== !
      'css/*.css'
    ])
    .pipe(concat('styles.css'))
    .pipe(autoprefix('last 2 versions'))
    .pipe(minifyCss())
    .pipe(gulp.dest('local/view/style/base/css/dist/'));
});