Remove unused component

Rather than port this to use `gl-pagination`, it turned out nothing
consumes it, so just remove it instead.

app/assets/javascripts/vue_shared/components/pagination/graphql_pagination.vue

-<script>
-import { GlButton } from '@gitlab/ui';
-import { PREV, NEXT } from '~/vue_shared/components/pagination/constants';
-
-/**
- * Pagination Component for graphql API
- */
-export default {
-  name: 'GraphqlPaginationComponent',
-  components: {
-    GlButton,
-  },
-  labels: {
-    prev: PREV,
-    next: NEXT,
-  },
-  props: {
-    hasNextPage: {
-      required: true,
-      type: Boolean,
-    },
-    hasPreviousPage: {
-      required: true,
-      type: Boolean,
-    },
-  },
-};
-</script>
-<template>
-  <div class="justify-content-center d-flex prepend-top-default">
-    <div class="btn-group">
-      <gl-button
-        class="js-prev-btn page-link"
-        :disabled="!hasPreviousPage"
-        @click="$emit('previousClicked')"
-        >{{ $options.labels.prev }}</gl-button
-      >
-
-      <gl-button
-        class="js-next-btn page-link"
-        :disabled="!hasNextPage"
-        @click="$emit('nextClicked')"
-        >{{ $options.labels.next }}</gl-button
-      >
-    </div>
-  </div>
-</template>

spec/javascripts/vue_shared/components/pagination/graphql_pagination_spec.js

-import { shallowMount, createLocalVue } from '@vue/test-utils';
-import GraphqlPagination from '~/vue_shared/components/pagination/graphql_pagination.vue';
-
-const localVue = createLocalVue();
-
-describe('Graphql Pagination component', () => {
-  let wrapper;
-  function factory({ hasNextPage = true, hasPreviousPage = true }) {
-    wrapper = shallowMount(localVue.extend(GraphqlPagination), {
-      propsData: {
-        hasNextPage,
-        hasPreviousPage,
-      },
-      localVue,
-    });
-  }
-
-  afterEach(() => {
-    wrapper.destroy();
-  });
-
-  describe('without previous page', () => {
-    beforeEach(() => {
-      factory({ hasPreviousPage: false });
-    });
-
-    it('renders disabled previous button', () => {
-      expect(wrapper.find('.js-prev-btn').attributes().disabled).toEqual('true');
-    });
-  });
-
-  describe('with previous page', () => {
-    beforeEach(() => {
-      factory({ hasPreviousPage: true });
-    });
-
-    it('renders enabled previous button', () => {
-      expect(wrapper.find('.js-prev-btn').attributes().disabled).toEqual(undefined);
-    });
-
-    it('emits previousClicked on click', () => {
-      wrapper.find('.js-prev-btn').vm.$emit('click');
-
-      expect(wrapper.emitted().previousClicked.length).toBe(1);
-    });
-  });
-
-  describe('without next page', () => {
-    beforeEach(() => {
-      factory({ hasNextPage: false });
-    });
-
-    it('renders disabled next button', () => {
-      expect(wrapper.find('.js-next-btn').attributes().disabled).toEqual('true');
-    });
-  });
-
-  describe('with next page', () => {
-    beforeEach(() => {
-      factory({ hasNextPage: true });
-    });
-
-    it('renders enabled next button', () => {
-      expect(wrapper.find('.js-next-btn').attributes().disabled).toEqual(undefined);
-    });
-
-    it('emits nextClicked on click', () => {
-      wrapper.find('.js-next-btn').vm.$emit('click');
-
-      expect(wrapper.emitted().nextClicked.length).toBe(1);
-    });
-  });
-});