dbt-metricflow incompatible with dbt-core>=1.12 despite docs listing dbt Core 1.12 as supported for latest metrics YAML spec

**Summary**
dbt-metricflow 0.13.0 (latest) pins dbt-core<1.12.0, but the [latest metrics YAML spec docs](https://docs.getdbt.com/docs/build/latest-metrics-spec) list dbt Core v1.12 as a supported environment. Users following the docs to use the new spec with dbt Core 1.12 cannot install dbt-metricflow to test locally via mf query — pip rejects the install due to the version conflict.

**Steps to reproduce**
python -m venv .venv && source .venv/bin/activate
pip install dbt-core==1.12.0
pip install dbt-metricflow

**Expected behavior**
dbt-metricflow installs successfully alongside dbt Core 1.12 and mf query works for local development.

**Actual behavior**
pip raises a dependency conflict:
`dbt-metricflow 0.13.0 requires dbt-core<1.12.0,>=1.10.4`

**Environment**
  - dbt-core: 1.12.0
  - dbt-metricflow: 0.13.0

**Additional context**
The [latest metrics YAML spec docs](https://docs.getdbt.com/docs/build/latest-metrics-spec) explicitly list dbt Core v1.12 as a supported environment alongside dbt platform and dbt Fusion. Users attempting to follow this path for local development hit a dead end with no documented workaround. The only current option is to downgrade to dbt Core 1.10.x, which does not support the new YAML spec.