Simplify the find expression

The `find` expression was a bit complex to grok and it did not remove the
`__pycache__` directories. It also missed removing the C-extension tests `*.so`
files.

Dockerfile-linux.template

@@ -227,12 +227,9 @@ RUN set -eux; \
 	cd /; \
 	rm -rf /usr/src/python; \
 	\
-	find /usr/local -depth \
-		\( \
-			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
-			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
-		\) -exec rm -rf '{}' + \
-	; \
+	find /usr/local -type d \( -name test -o -name idle_test -o -name __pycache__ \) -exec rm -rf '{}' +; \
+	find /usr/local -type f -name libpython3*.a -delete; \
+	find /usr/local -type f -name *test*.so -delete; \
 	\
 {{ if is_alpine then ( -}}
 	find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec scanelf --needed --nobanner --format '%n#p' '{}' ';' \