chore: update CHANGELOG and ABI dumps (#5786)

* chore: update CHANGELOG and ABI dumps

Author: scotthart

CHANGELOG.md

@@ -32,24 +32,40 @@
   - If you have any feedback about this change please add comments in
     [#5726](https://github.com/googleapis/google-cloud-cpp/issues/5726)
 
+## v1.25.0 - TBD
 
-## v1.24.0 - TBD
+## v1.24.0 - 2021-02
 
-### Bazel
+**NOTE**:
+We are clarifying our approach to backwards compatibility beyond the C++ API.
+See the [README.md](README.md) on GitHub for details
 
+### Bazel
 * Starting with this release the legacy targets, such as
   `//google/cloud/pubsub:pubsub_client` are deprecated and generate warnings
   recommending a replacement (such as `//:pubsub`). Note that you may have to
   prefix the target with the external package name you gave this library, e.g.,
-  `@github_com_google_cloud_cpp//:pubsub`.
+  `@github_com_google_cloud_cpp//:pubsub`. (#5746)
 
-### Storage
+### Bigtable
+* feat(bigtable): restore from backups in other instance (#5754)
+* feat(bigtable): better control over channel refresh (#5753)
 
-**BREAKING CHANGES**:
+### Spanner
+No user-facing changes.
 
+### Storage
+**BREAKING CHANGES**:
 * UniformBucketLevelAccess was known as BucketPolicyOnly during the beta. For
   compatibility the C++ Cloud Storage library supported both, however
-  BucketPolicyOnly is now completely removed.
+  BucketPolicyOnly is now completely removed. (#5720)
+
+**Other Changes**:
+* feat(storage): Support includeTrailingDelimiter in Client::ListObjects (#5713)
+
+### Common Libraries
+**BREAKING CHANGES**:
+* refactor!: removed old bigquery code (#5722)
 
 ## v1.23.0 - 2021-01