Relax check_dist_restriction for dry run

There does not seem to be any reason to require `--only-binary` or
`--no-deps` in dry run mode. There is also no need to specify
`--target` in such a situation.

With the new `--report` flag, this makes it possible to use `pip` just
as a cross-platform dependency resolver.

news/11764.feature.rst

@@ -0,0 +1,2 @@
+Relax ``check_dist_restriction`` for dry run so one can more easily use ``pip`` as a cross platform
+dependency resolver.

src/pip/_internal/cli/cmdoptions.py

@@ -79,6 +79,11 @@ def check_dist_restriction(options: Values, check_target: bool = False) -> None:
         options.format_control != binary_only and not options.ignore_dependencies
     )
 
+    if hasattr(options, "dry_run") and options.dry_run:
+        # In dry run mode nothing will be downloaded or installed, so sdist are OK and
+        # there is no need to specify `--target`.
+        return
+
     # Installations or downloads using dist restrictions must not combine
     # source distributions and dist-specific wheels, as they are not
     # guaranteed to be locally compatible.

tests/functional/test_install.py

@@ -2324,6 +2324,23 @@ def test_install_dry_run(script: PipTestEnvironment, data: TestData) -> None:
     assert "Successfully installed" not in result.stdout
 
 
+def test_install_dry_run_with_dist_restriction(
+    script: PipTestEnvironment, data: TestData
+) -> None:
+    """Test that pip install --dry-run logs what it would install."""
+    result = script.pip(
+        "install",
+        "--dry-run",
+        "--platform",
+        "linux_x86_64",
+        "--find-links",
+        data.find_links,
+        "simple",
+    )
+    assert "Would install simple-3.0" in result.stdout
+    assert "Successfully installed" not in result.stdout
+
+
 def test_install_8559_missing_wheel_package(
     script: PipTestEnvironment, shared_data: TestData
 ) -> None: