test: remove RxJS from E2E process utility

Replaces RxJS-based retry logic in `execAndWaitForOutputToMatch` with
standard async/await for better readability and reduced dependency footprint.

Author: clydin

tests/legacy-cli/e2e/utils/BUILD.bazel

@@ -19,7 +19,6 @@ ts_project(
         "//:node_modules/verdaccio",
         "//:node_modules/verdaccio-auth-memory",
         "//tests:node_modules/@types/tar-stream",
-        "//tests:node_modules/rxjs",
         "//tests:node_modules/tar-stream",
         "//tests:node_modules/tree-kill",
     ],

tests/legacy-cli/e2e/utils/process.ts

@@ -1,6 +1,5 @@
 import { spawn, SpawnOptions } from 'node:child_process';
 import * as child_process from 'node:child_process';
-import { concat, defer, EMPTY, from, lastValueFrom, catchError, repeat } from 'rxjs';
 import { getGlobalVariable, getGlobalVariablesEnv } from './env';
 import treeKill from 'tree-kill';
 import { delimiter, join, resolve } from 'node:path';
@@ -310,7 +309,7 @@ export async function execAndCaptureError(
   }
 }
 
-export function execAndWaitForOutputToMatch(
+export async function execAndWaitForOutputToMatch(
   cmd: string,
   args: string[],
   match: RegExp,
@@ -322,15 +321,24 @@ export function execAndWaitForOutputToMatch(
     // happened just before the build (e.g. `git clean`).
     // This seems to be due to host file system differences, see
     // https://nodejs.org/docs/latest/api/fs.html#fs_caveats
-    return lastValueFrom(
-      concat(
-        from(_exec({ waitForMatch: match, env }, cmd, args)),
-        defer(() => waitForAnyProcessOutputToMatch(match, 2500)).pipe(
-          repeat(20),
-          catchError(() => EMPTY),
-        ),
-      ),
-    );
+    const maxRetries = 20;
+    let lastError;
+
+    try {
+      return await _exec({ waitForMatch: match, env }, cmd, args);
+    } catch (e) {
+      lastError = e;
+    }
+
+    for (let i = 0; i < maxRetries; i++) {
+      try {
+        return await waitForAnyProcessOutputToMatch(match, 2500);
+      } catch (e) {
+        lastError = e;
+      }
+    }
+
+    throw lastError;
   } else {
     return _exec({ waitForMatch: match, env }, cmd, args);
   }