Bump version to 0.16.0 (breaking)

Removing the EinExprs extension drops the `alg = "einexpr"` contraction
sequence algorithm, so this is a breaking change. Bump the root package
to 0.16.0 and update the pinned version in test/, docs/, and examples/
Project.toml files to match.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mtfishman

Project.toml

@@ -1,6 +1,6 @@
 name = "ITensorNetworks"
 uuid = "2919e153-833c-4bdc-8836-1ea460a35fc7"
-version = "0.15.27"
+version = "0.16.0"
 authors = ["Matthew Fishman <mfishman@flatironinstitute.org>, Joseph Tindall <jtindall@flatironinstitute.org> and contributors"]
 
 [workspace]

docs/Project.toml

@@ -16,7 +16,7 @@ path = ".."
 Documenter = "1.10"
 Graphs = "1"
 ITensorFormatter = "0.2.27"
-ITensorNetworks = "0.15"
+ITensorNetworks = "0.16"
 ITensors = "0.9"
 Literate = "2.20.1"
 NamedGraphs = "0.8.2"

examples/Project.toml

@@ -5,4 +5,4 @@ ITensorNetworks = "2919e153-833c-4bdc-8836-1ea460a35fc7"
 path = ".."
 
 [compat]
-ITensorNetworks = "0.15"
+ITensorNetworks = "0.16"

test/Project.toml

@@ -46,7 +46,7 @@ Glob = "1.3.1"
 Graphs = "1.12"
 GraphsFlows = "0.1.1"
 ITensorMPS = "0.3.6"
-ITensorNetworks = "0.15"
+ITensorNetworks = "0.16"
 ITensorPkgSkeleton = "0.3.42"
 ITensors = "0.7, 0.8, 0.9"
 KrylovKit = "0.8, 0.9, 0.10"