run-success.mk: Record last successful run

Add a run-success.mk which provides a $(RUN_SUCCESS_CREATE_MARKER)
variable, and include it from run.mk and py-run.mk. If it's not overridden,
it logs the current commit to a marker file if the run succeeds. The marker
file is ignored from Git and cleaned in the context of the distclean
target.

The machinery can be customized by variables:

  RUN_SUCCESS_MARKER is the name of the marker file
  RUN_SUCCESS_RECORD_CMD is the generator for its content

For example, putting this into local.mk or jw-pkg/make/local.mk will record
the hashes of every repository in the entire workspace:

  define RUN_SUCCESS_RECORD_CMD
  make git-log-1
  make git-log-tree-1
  endef

Signed-off-by: Jan Lindemann <jan@janware.com>

.gitignore

@@ -20,7 +20,6 @@
 *tmp*
 *~
 .cache-project.mk
-.cache-projects.mk
 .exrc
 .feedfs_history
 .gdb_history
@@ -38,20 +37,19 @@ bin/*.tcl
 conftest.py
 core
 dist
+last-successful-run.txt
 ld-*.conf
 local.conf
 local.mk
-local.mk
 local.yaml
 make/*.pc
-make/ssh-wrapper.sh
 mkspec.sh
 pr-descr*.txt
 pre-local.mk
 pyproject.toml
 pyrightconfig.json
 test-out.txt
-test/integration/jw-pkg/projects/cache/test-pyproject.toml
-test/integration/jw-pkg/projects/cache/test-pyrightconfig.json
 !*.jw-tmpl
 !*.tmpl
+.cache-projects.mk
+make/ssh-wrapper.sh