package:build_test was being used only for its small, simple InMemoryAssetWriter implementation. I moved the implementation to package:contracts_generator and removed dependency on package:build_test which was introducing quite a deep dependency tree and blocking upgrades of other packages.
package:build_testwas being used only for its small, simpleInMemoryAssetWriterimplementation. I moved the implementation topackage:contracts_generatorand removed dependency onpackage:build_testwhich was introducing quite a deep dependency tree and blocking upgrades of other packages.