chore: add babel/core to peer dependencies

[cometkim]

Description

I've got errors when tried to using yarn@berry which doesn't support implicit transitive peer deps anymore.

➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/plugin-proposal-class-properties@npm:7.5.5
➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/plugin-proposal-optional-chaining@npm:7.2.0
➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/plugin-syntax-dynamic-import@npm:7.2.0
➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/plugin-transform-runtime@npm:7.5.5
➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/preset-env@npm:7.5.5
➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/preset-flow@npm:7.0.0
➤ YN0002: │ babel-preset-gatsby-package@npm:0.2.3 doesn't provide @babel/core@^7.0.0-0 requested by @babel/preset-react@npm:7.0.0

I added missing peer dependencies into the package.json of two packages:

• babel-preset-gatsby-package
• gatsby-plugin-typescript (also has a similar issue, gatsby-plugin-typescript missing dependency on @babel/core and graphql #20900)

Note

I know @Austaras requested removing @babel/plugin-proposal-nullish-coalescing-operator and @babel/plugin-proposal-optional-chaining from gatsby-plugin-typescript.

I think it's better to deal with another PR because removing the two plugins requires to raise existing gatsby peer dependency version from 2.0.0 to at least 2.18.11

Related Issues

Fixes #20900

[cometkim]

also related #20949

[wardpeet]

I'm unsure if we should add @babel/core as a peerdep or a regular dep for typescript-plugin. I'm leaning more forward to dependency as users don't have to care about installing @babel/core as well.

[cometkim]

I'm unsure if we should add @babel/core as a peerdep or a regular dep for typescript-plugin. I'm leaning more forward to dependency as users don't have to care about installing @babel/core as well.

@wardpeet Ah, you right. @babel/core as dep for the typescript-plugin makes more sense to me either.

[cometkim]

note there is no change in the lockfile

[wardpeet]

Thank you! this looks great.

[bradleyayers]

Thanks for this! Amazing.