Import of MastraStorage class is not pure

[wardpeet]

When importing stores like @mastra/pg it also imports libsql (default storage) class which is not ideal when using it inside frameworks like NextJS. It means libsql always eeds to be installed even if you're using pg vector utils.

Problem:

const pgVector = new PgVector(process.env.POSTGRES_CONNECTION_STRING!)
const mastraResults = await pgVector.query('embeddings', embedding, 10)