Improve Docker-based build

The `--version` command now will show git metadata.
The build is done on an older version of Debian, too, for older
glibc linking.

.dockerignore

@@ -1,9 +1,4 @@
 .buildx-cache
-.git
-.gitattributes
-.github
-.gitignore
-.gitattributes
 CHANGELOG.md
 README.md
 docs

Dockerfile

@@ -1,7 +1,15 @@
 ################################################################################
 # Build `noseyparker`
+#
+# We use the oldest Debian-based image that can build Nosey Parker without trouble.
+# This is done in an effort to link against an older glibc, so that the built
+# binary (which is *not* statically linked, but does not dynamically link with
+# non-standard runtime libraries) can be copied out of the container and run on
+# more Linux machines than would otherwise be possible.
+#
+# See https://github.com/praetorian-inc/noseyparker/issues/58.
 ################################################################################
-FROM rust:1.70 AS builder
+FROM rust:1.71-bullseye AS builder
 
 # Install dependencies
 #