fix: update makefile to execute build_schema twice

[ocobles]

Changes:

• duplicate build_schema target (build and build_schema_post_examples) to be able to execute it twice (it didn't work even adding build_schema in PHONY). I was debugging leaving some traces to check that now it is executed twice, as expected.
• Check that the pulumi cli installed version is the same as the one defined in provider/go.mod
• Add export PATH := $(BIN_DIR):$(PATH). The pulumi converter command uses several plugins, on the one hand the source converter (yaml and terraform plugins in our case) and on the other hand the sdk of the language to which it is being converted, pulumi-language-python / pulumi-language-go / etc. Although the correct Pulumi CLI binary was being used with .pulumi/bin/pulumi convert ... it was taking the language binary from $PATH, so in my case /opt/homebrew/bin/ which corresponded to the Pulumi v3.122.0 version instead of the new installed v3.128.0

Originally added to #161 and opening a new PR as per #161 (comment) suggestion

[github-actions]

Does the PR have any schema changes?

Does the PR have any schema changes?

Looking good! No breaking changes found.
No new resources/functions.

Maintainer note: consult the runbook for dealing with any breaking changes.

[github-actions]

This PR is included in version 0.15.0 🎉