Don't try to push store paths that were GCed

Previously we'd only push unique paths before/after the job,
but that's not good enough because someone might run garbage
collection.

Now we only push unique store paths that are in the list of
when the job finished.

dist/main/index.js

@@ -971,6 +971,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
 };
 Object.defineProperty(exports, "__esModule", { value: true });
 const core = __importStar(__webpack_require__(470));
+const child_process_1 = __webpack_require__(129);
 const coreCommand = __importStar(__webpack_require__(431));
 const exec = __importStar(__webpack_require__(986));
 exports.IsPost = !!process.env['STATE_isPost'];
@@ -1010,7 +1011,7 @@ function upload() {
         try {
             if (signingKey !== "" && skipPush !== 'true') {
                 core.startGroup('Cachix: pushing paths');
-                yield exec.exec("sh", ["-c", `nix path-info --all | grep -v '\.drv$' | cat - /tmp/store-path-pre-build | sort | uniq -u  | ${cachixExecutable} push ${name}`]);
+                child_process_1.execFileSync(`${__dirname}/push-paths.sh`, { stdio: 'inherit' });
                 core.endGroup();
             }
         }

dist/main/push-paths.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+comm -13 <(sort /tmp/store-path-pre-build) <(nix path-info --all | grep -v '\.drv$') | $1 push $2