vtk 9.2.6 or 9.3.0 are used by feedstock, but migrations are done for 9.3.1

[traversaro]

Solution to issue cannot be found in the documentation.

• [X] I checked the documentation.

Issue

Trying to install the latest version of two packages with complex dependency structures (gazebo and pcl) I am obtaining an error:

Channels:
Channels:
 - robostack-staging
 - conda-forge
Platform: linux-64
Collecting package metadata (repodata.json): done
Solving environment: failed

LibMambaUnsatisfiableError: Encountered problems while solving:
  - package gazebo-11.14.0-gzcompatnamehb9ef551_17 requires libgdal-core >=3.9.2,<3.10.0a0, but none of the providers can be installed

Could not solve for environment specs
The following packages are incompatible
├─ gazebo 11.14.0 *_17 is installable and it requires
│  └─ libgdal-core >=3.9.2,<3.10.0a0  with the potential options
│     ├─ libgdal-core 3.9.2 would require
│     │  └─ proj >=9.4.1,<9.5.0a0 , which can be installed;
│     └─ libgdal-core 3.9.2 would require
│        └─ proj >=9.5.0,<9.6.0a0 , which can be installed;
└─ pcl 1.14.1 *_5 is not installable because it requires
   └─ vtk-base >=9.3.0,<9.3.1.0a0 , which requires
      └─ proj >=9.3.1,<9.3.2.0a0 , which conflicts with any installable versions previously reported.

Channels:: command not found

The problem seems that existing feedstocks either use vtk==9.2.6 (version currently pinned in global pinnings) or vtk==9.3.0 (version currently under migration). However, ABI migration PRs are happening for vtk 9.3.1 (see https://github.com/conda-forge/vtk-feedstock/pull/342 and https://github.com/conda-forge/vtk-feedstock/pull/345), so basically vtk 9.2.6/9.3.0 are not migrated.

Possible solution includes:

• Create 9.2.6 or 9.3.0 branches to also do abi migrations for those versions. I am not a big fan of these as these increase the burden for vtk mantainers.
• Close 9.3.0 migration and start 9.3.1 migration. Personally I prefer this solution as anyhow we need to migrate to 9.3.1 sooner or later, so we reduce the duplicated work.

fyi @conda-forge/vtk

Installed packages

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Environment info

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[traversaro]

Close 9.3.0 migration and start 9.3.1 migration. Personally I prefer this solution as anyhow we need to migrate to 9.3.1 sooner or later, so we reduce the duplicated work.

I implemented this solution in https://github.com/conda-forge/conda-forge-pinning-feedstock/pull/6435 .