GridKit release 0.2

[pelesh]

Description

Last preparation before 0.2 release. Milestone "Release 0.2" is complete and we are ready for the release.

Proposed changes

• Update GridKit version to 0.2
• Update SUNDIALS dependency version in CMake to 7.8.

Checklist

• All tests pass.
• Code compiles cleanly with flags -Wall -Wpedantic -Wconversion -Wextra.
• The new code follows GridKit™ style guidelines.
• There are unit tests for the new code.
• The new code is documented.
• The feature branch is rebased with respect to the target branch.
• N/A The CHANGELOG.md has been updated to reflect the changes. If this is a minor PR that is part of a larger fix already included in the file, state so.

Further comments

Please bring up here last minute fixes needed for the release.

[superwhiskers]

i already compile with sundials 7.9 so this is fine