bug 1746940: update stackwalker to 1869d3a0 (past v0.18.0)

This updates the stackwalker to a commit that's v0.18.0 plus the fix for
codeinfo lookup and the fix for path parsing (bug #1746940).

Author: willkg

bin/build_stackwalker.sh

@@ -15,8 +15,8 @@ set -euo pipefail
 
 # From: https://github.com/rust-minidump/rust-minidump
 # NOTE(willkg): This is just a bit after v0.18.0.
-MINIDUMPREV=3819edf
-MINIDUMPREVDATE=2023-10-12
+MINIDUMPREV=1869d3a0
+MINIDUMPREVDATE=2023-10-13
 
 TARFILE="socorro-stackwalker.${MINIDUMPREVDATE}.${MINIDUMPREV}.tar.gz"