ci: pin the mongo sidecar image to 7.0

MongoDB 8.x images refuse to start on Linux kernels 6.19 through 7.0.13
(SERVER-121912, bundled TCMalloc incompatibility), and the refreshed
GitHub runner image carries an affected kernel — every Cypress shard
scheduled on one fails during setup. MongoDB 7.0 is unaffected and well
within the supported range.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: wyattwalter

.github/workflows/ci-test-custom-script.yml

@@ -62,7 +62,7 @@ jobs:
           # Opens tcp port 6379 on the host and service container
           - 6379:6379
       mongo:
-        image: mongo
+        image: mongo:7.0
         ports:
           - 27017:27017
 

.github/workflows/ci-test-hosted.yml

@@ -42,7 +42,7 @@ jobs:
           # Opens tcp port 6379 on the host and service container
           - 6379:6379
       mongo:
-        image: mongo
+        image: mongo:7.0
         ports:
           - 27017:27017
 

.github/workflows/ci-test-limited-with-count.yml

@@ -80,7 +80,7 @@ jobs:
           # Opens tcp port 6379 on the host and service container
           - 6379:6379
       mongo:
-        image: mongo
+        image: mongo:7.0
         ports:
           - 27017:27017
 

.github/workflows/ci-test-limited.yml

@@ -56,7 +56,7 @@ jobs:
         ports:
           - 6379:6379
       mongo:
-        image: mongo
+        image: mongo:7.0
         ports:
           - 27017:27017
 

.github/workflows/ci-test-playwright.yml

@@ -53,7 +53,7 @@ jobs:
         ports:
           - 6379:6379
       mongo:
-        image: mongo
+        image: mongo:7.0
         ports:
           - 27017:27017
 

.github/workflows/external-pr-validation.yml

@@ -115,7 +115,7 @@ jobs:
         ports:
           - 6379:6379
       mongo:
-        image: mongo
+        image: mongo:7.0
         ports:
           - 27017:27017
     defaults: