* fix Print, is_empty, read_file test=document_fix

* cherry-pick fix prroi op test=develop test=release/1.6

test=develop
test=release/1.6
test=document_fix

cherry pick 91693b9c and resolve conflict in API.spec, test=document_fix (#20477)

modify en api doc

- leaky_relu
- less_than 
- log
- logical_and
- logical_or
- logical_xor
- logical_not

* fix some en doc test=develop test=document_fix

* fix new fluid.data API.spec test=develop test=document_fix

* fix typo test=develop, test=document_fix

* fix typo test=develop test=document_fix

* fix typo test=develop test=document_fix

* fix test=develop test=document_fix

* fix according review test=develop test=document_fix

* fix review test=develop test=document_fix

* fix according review advice test=develop test=document_fix

* fix the doc  test=develop test=document_fix

* fix API.spec test=develop test=document_fix

Cherrypick  en doc: reorder_lod_tensor_by_rank , map_reader, WeightNormParamAttr, io.compose  (#20463)

* modify map_reader en doc (#20229)

* modify WeightNormParamAttr en doc (#20218)

* modify reorder_lod_tensor_by_rank en doc

* modify compose en doc (#20217)

refine en api doc of [shape, scale, split, selu, soft_relu, scatter], test=develop, test=document_fix (#20264) (#20458)

* add new save load interface; test=develop

* add new save interface; test=develop

* add save load interface ;

* fix save load error;

* fix dygraph set dict bug;

* add save load unit test; test=develop

* fix test_imperative_optimizer bug; test=develop

* fix unitest optimizer bug; test=develop

* fix code coverage; test=develop

* fix converage; test=develop

* add document for apis; test=develop

* fix unitest error; test=develop

* fix save load unit test error; test=develop

* fix error message; test=develop

* change set_parameter set_optimizer to save_dygraph; test=develop

* add load_graph check; test=develop

* fix api spec; test=develop

Fix the api input type and data dtype check in the op of sign
test=release/1.6

* fix the reduce api en doc test=document_fix test=develop

* fix the fluid.data test=develop test=document_fix

* fix the API.spec test=develop test=document_fix

* fix according the review test=develop test=document_fix

* fix the confilict test=develop test=document_fix

update the api en_doc of has_inf, has_nan, cumsum, double_buffer and mul

* add api check in fc test=develop

* enforce shape error info of sum op test=develop

* fix spelling test=develop

* print x_dims info test=develop

* enhance shape error info test=develop

test=release/1.6, test=document_fix

test=release/1.6, test=document_fix

test=release/1.6, test=document_fix

* refine en doc. test=develop. test=document_fix

enhance shape error messages for reshape op.
test=release/1.6

test=release/1.6

* cherry-pick fix en doc test=develop test=document_fix

* roll back fsp_matrix hash test=develop test=document_fix

Fix english doc api, invloves the op of retinanet_target_assign, sigmoid_focal_loss and retinanet_detection_output, cherry-pick, (#20419)

test=release/1.6
test=document_fix

* test=develop, fix docker with paddle nccl problem

* test=develop, refine en_doc for Variable and Program

* test=document_fix, fix English doc for Variable and Program

* test=document_fix, refine astype code block style

* test=document_fix, add example code for Variable properties

test=release/1.6, test=document_fix

* Fix some english doc api, shenze tools group, cherry-pick(#20300)
test=release/1.6
test=document_fix

* remote the unless change from cherry-pick
test=release/1.6
test=document_fix

* Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into api_fix

* test=release/1.6, test=document_fix

* fix en api doc test=develop test=document_fix test=document_preview

* update api.spec  test=develop test=document_fix test=document_preview

* fix some details  test=develop test=document_fix test=document_preview

* update API.spec test=document_fix test=document_preview  test=develop

* cherry pick for 131b1dc3, test=develop, test=document_fix

* cherry pick for fb21a743, test=develop, test=document_fix

[cherry-pick]fix English document of expand/pow/reshape/slice. test=release/1.6, test=document_fix (#20280) (#20356)

* fix api 1.6 doc bpr, data_norm teacher_student