fix(core): avoid panic when workflow channels close#1165

sachinsharma3191 wants to merge 6 commits intotemporalio:maintemporalio/sdk-rust:mainfrom

sachinsharma3191:issue-692-no-panic-on-unauthorizedsachinsharma3191/sdk-core:issue-692-no-panic-on-unauthorizedCopy head branch name to clipboard