Generate release notes for 3.8.4

Author: github-actions[bot]

doc/manual/source/SUMMARY.md.in

@@ -130,6 +130,7 @@
   - [Contributing](development/contributing.md)
 - [Determinate Nix Release Notes](release-notes-determinate/index.md)
   - [Changes between Nix and Determinate Nix](release-notes-determinate/changes.md)<!-- next -->
+  - [Release 3.8.4 (2025-07-21)](release-notes-determinate/rl-3.8.4.md)
   - [Release 3.8.3 (2025-07-18)](release-notes-determinate/rl-3.8.3.md)
   - [Release 3.8.2 (2025-07-12)](release-notes-determinate/rl-3.8.2.md)
   - [Release 3.8.1 (2025-07-11)](release-notes-determinate/rl-3.8.1.md)

doc/manual/source/release-notes-determinate/changes.md

@@ -1,6 +1,6 @@
 # Changes between Nix and Determinate Nix
 
-This section lists the differences between upstream Nix 2.30 and Determinate Nix 3.8.3.<!-- differences -->
+This section lists the differences between upstream Nix 2.30 and Determinate Nix 3.8.4.<!-- differences -->
 
 * In Determinate Nix, flakes are stable. You no longer need to enable the `flakes` experimental feature.
 
@@ -116,3 +116,7 @@ This section lists the differences between upstream Nix 2.30 and Determinate Nix
 * Add an `external-builders` experimental feature by @cole-h in [DeterminateSystems/nix-src#141](https://github.com/DeterminateSystems/nix-src/pull/141)
 
 * Add support for external builders by @edolstra in [DeterminateSystems/nix-src#78](https://github.com/DeterminateSystems/nix-src/pull/78)
+
+<!-- Determinate Nix version 3.8.4 -->
+
+* Revert "Use WAL mode for SQLite cache databases" by @grahamc in [DeterminateSystems/nix-src#155](https://github.com/DeterminateSystems/nix-src/pull/155)

doc/manual/source/release-notes-determinate/rl-3.8.4.md

@@ -0,0 +1,9 @@
+# Release 3.8.4 (2025-07-21)
+
+* Based on [upstream Nix 2.30.1](../release-notes/rl-2.30.md).
+
+## What's Changed
+* Revert "Use WAL mode for SQLite cache databases" by @grahamc in [DeterminateSystems/nix-src#155](https://github.com/DeterminateSystems/nix-src/pull/155)
+
+
+**Full Changelog**: [v3.8.3...v3.8.4](https://github.com/DeterminateSystems/nix-src/compare/v3.8.3...v3.8.4)