As the title says. These tasks should be batched because they can arise from ILM actions.

Relates #77466
server/src/test/java/org/elasticsearch/cluster/metadata/MetadataIndexAliasesServiceTests.java
final ResourceNotFoundException iae = expectThrows(
            ResourceNotFoundException.class,
            () -> service.applyAliasActions(finalCS, singletonList(new AliasAction.Remove(index, "test_2", true)))
        );
        assertThat(iae.getMessage(), containsString("required alias [test_2] does not exist"));
    }
    public void testMultipleIndices() {
        final var length = randomIntBetween(2, 8);
        final Set<String> indices = Sets.newHashSetWithExpectedSize(length);
        ClusterState before = ClusterState.builder(ClusterName.DEFAULT).build();
        final var addActions = new ArrayList<AliasAction>(length);
        for (int i = 0; i < length; i++) {
            final String index = randomValueOtherThanMany(v -> indices.add(v) == false, () -> randomAlphaOfLength(8));
            before = createIndex(before, index);
            addActions.add(new AliasAction.Add(index, "alias-" + index, null, null, null, null, null));
        }
        final ClusterState afterAddingAliasesToAll = service.applyAliasActions(before, addActions);
        assertAliasesVersionIncreased(indices.toArray(new String[0]), before, afterAddingAliasesToAll);
        
        final Set<String> randomIndices = Sets.newHashSetWithExpectedSize(length);
        final var randomAddActions = new ArrayList<AliasAction>(length);
        for (var index : indices) {
            if (randomBoolean()) {
                randomAddActions.add(new AliasAction.Add(index, "random-alias-" + index, null, null, null, null, null));
                randomIndices.add(index);
            }
        }
        final ClusterState afterAddingRandomAliases = service.applyAliasActions(afterAddingAliasesToAll, randomAddActions);
        assertAliasesVersionIncreased(randomIndices.toArray(new String[0]), afterAddingAliasesToAll, afterAddingRandomAliases);
        assertAliasesVersionUnchanged(