[cmd/builder] Provide better error or have main.go template be conditional on otelcol_version

[mx-psi]

Describe the bug

If building a Collector with otelcol_version set to v0.88.0 or below with a builder with v0.89.0 or above it will fail to build.

Steps to reproduce

See https://github.com/kenfinnigan/otel-collector-builder-reproducer

What did you expect to see?

The Collector can be built successfully or, alternatively, a clear error message tells me what to do.

What did you see instead?

./main.go:20:70: cannot use components (value of type func() (otelcol.Factories, error)) as otelcol.Factories value in struct literal
make: *** [Makefile:52: otelcontribcolbuilder] Error 1

Additional context

This happens because #8478 broke builds for otelcol_version lower than v0.89.0. On #8713 there is an example of doing this kind of change while avoiding breakage for older Collector versions. I guess the question remains on how much compatibility we want to have with older versions, but since this is easy to handle, I think we should keep compatibility for now.