cli: Build IDL if there is only one program when using the idl build command

[acheroncrypto]

Problem

Running the idl build command when there is only one program inside the workspace root results in an error:

$ anchor idl build
Error: Not in a program directory

You need to specify which program's IDL to build if the current directory is not a program directory:

anchor idl build -p <PROGRAM_NAME>

This is unnecessary when there is only one program in the workspace.

Summary of changes

Build IDL if there is only one program inside the workspace when using the idl build command outside of a program directory.

[vercel]

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