MRG: update Makefile with 'offline', 'wheel' (#3579)

Fixes #3571

Updates `include/sourmash.h` rule to be verbose;
Adds `wheel` and `offline` targets for build.

Author: ctb

Makefile

@@ -14,9 +14,15 @@ clean:
 
 install: build
 
+offline:
+	pip install -e . --no-index --find-links '.' --no-build-isolation
+
 dist: FORCE
 	$(PYTHON) -m build --sdist
 
+wheel:
+	$(PYTHON) -m maturin build -r
+
 test: .PHONY
 	tox -e py310
 	cargo nextest run
@@ -36,7 +42,7 @@ include/sourmash.h: src/core/src/lib.rs \
                     src/core/src/errors.rs \
                     src/core/cbindgen.toml
 	cd src/core && \
-	RUSTC_BOOTSTRAP=1 cbindgen -c cbindgen.toml . -o ../../$@
+	RUSTC_BOOTSTRAP=1 cbindgen -c cbindgen.toml . -o ../../$@ -v
 
 coverage: all
 	tox -e coverage