Fix bug in `rhat_summary()` when sigma is a vector.

PiperOrigin-RevId: 784044367

Convert a stateful (int) seed into a stateless (tuple) seed in `sampl…

…e_posterior` to ensure the sampling is deterministic.

PiperOrigin-RevId: 783094677

Bump v1.1.5

PiperOrigin-RevId: 782075568

Bump 1.1.4

PiperOrigin-RevId: 777656371

cut v1.1.3

PiperOrigin-RevId: 775393954

- cut release 1.1.2

- Also: update getting started guide to use
`DataFrameDataBuilder`.

PiperOrigin-RevId: 771241788

Bump Meridian version to 1.1.1.

PiperOrigin-RevId: 764449773

Bump Meridian version to 1.1.0.

PiperOrigin-RevId: 761723904

Bump Meridian v1.0.9

PiperOrigin-RevId: 748888612

Release Meridian v1.0.8

PiperOrigin-RevId: 747559232