also retry git push and switch to zx's builtin retry

autogitmerge.mjs

 #!/usr/bin/env zx
 import 'zx/globals'
+import { retry, expBackoff } from 'zx/experimental'
 import {default as parseDuration} from 'parse-duration'
 
 const configData = await fs.readFile(argv['config'] || './config.yaml', 'utf-8')
@@ -24,20 +25,10 @@ if (!fs.existsSync(wd)) {
 }
 
 cd(wd)
-let fetchErrors = 0, reportedConflictHashes
+let reportedConflictHashes
 while (true) {
-  try {
-    await $`git fetch --all`
-  } catch (e) {
-    echo('Error fetching')
-    fetchErrors++
-    if (fetchErrors > 10) {
-      throw e
-    }
-    await sleep(interval)
-  }
+  await retry(30, expBackoff(), () => $`git fetch --all`)
 
-  fetchErrors = 0
   await $`git reset --hard project/${config.project.branch}`
   let mergeSuccess = true;
   try {
@@ -86,7 +77,7 @@ ${gitOutput}
     }
   }
   if (mergeSuccess) {
-    await $`git push project ${config.project.branch}`
+    await retry(30, expBackoff(), () => $`git push project ${config.project.branch}`)
   }
   await sleep(interval)
 }