Add satisfiability tests.

Author: hameerabbasi

crates/pixi_core/src/lock_file/satisfiability/snapshots/pixi_core__lock_file__satisfiability__tests__failing_satisiability@changed-env-marker.snap

@@ -0,0 +1,7 @@
+---
+source: crates/pixi_core/src/lock_file/satisfiability/mod.rs
+expression: s
+---
+environment 'default' does not satisfy the requirements of the project for platform 'osx-arm64'
+    Diagnostic severity: error
+    Caused by: the requirement 'numpy==2.* ; sys_platform == 'darwin'' could not be satisfied (required by '<environment>')

tests/data/non-satisfiability/changed-env-marker/pixi.lock

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+[workspace]
+authors = ["Hameer Abbasi <2190658+hameerabbasi@users.noreply.github.com>"]
+channels = ["conda-forge"]
+name = "sattest"
+platforms = ["osx-arm64"]
+version = "0.1.0"
+
+[tasks]
+
+[dependencies]
+python = "3.11.*"
+
+[pypi-dependencies]
+numpy = { version = "==2.*", env-markers = "sys_platform == 'darwin'" }

tests/data/non-satisfiability/changed-env-marker/pixi.toml

@@ -0,0 +1,14 @@
+[workspace]
+authors = ["Hameer Abbasi <2190658+hameerabbasi@users.noreply.github.com>"]
+channels = ["conda-forge"]
+name = "sattest"
+platforms = ["osx-arm64"]
+version = "0.1.0"
+
+[tasks]
+
+[dependencies]
+python = "3.11.*"
+
+[pypi-dependencies]
+numpy = { version = "==2.*", env-markers = "sys_platform == 'linux'" }