Merge branch 'dev-1.x' of github.com:open-mmlab/mmsegmentation into 1.x

Merge branch 'dev-1.x' of github.com:open-mmlab/mmsegmentation into 1.x

bump v0.30.0 (open-mmlab#2462)

Merge branch 'dev-1.x' into 1.x

Merge pull request open-mmlab#2385 from open-mmlab/dev-1.x

Merge MMSegmentation 1.x development branch dev-1.x to main branch 1.x for v1.0.0rc2

Merge pull request open-mmlab#2257 from xiexinch/bumpv0.29.1

bumpv0.29.1

Merge pull request open-mmlab#2252 from MeowZheng/v1.0.0rc1

Bump V1.0.0rc1

Bump v0.29.0 (open-mmlab#2167)

* bump v0.29.0

* remove 2159

Bump v0.28.0 (open-mmlab#2047)

* bump v0.28.0

* update

Add changelog for MMSeg 1.0.0rc0 (open-mmlab#2007)

* Bump 1.0.0rc0

* rephase

* rephase