Adds 8.17.8 release notes (#1826)

* port elastic/elastic-agent#8647 to docs

* Update docs/en/ingest-management/release-notes/release-notes-8.17.asciidoc

Author: colleenmcginnis

docs/en/ingest-management/release-notes/release-notes-8.17.asciidoc

@@ -14,6 +14,7 @@
 
 This section summarizes the changes in each release.
 
+* <<release-notes-8.17.8>>
 * <<release-notes-8.17.7>>
 * <<release-notes-8.17.6>>
 * <<release-notes-8.17.5>>
@@ -28,6 +29,36 @@ Also see:
 * {kibana-ref}/release-notes.html[{kib} release notes]
 * {beats-ref}/release-notes.html[{beats} release notes]
 
+// begin 8.17.8 relnotes
+
+[[release-notes-8.17.8]]
+== {fleet} and {agent} 8.17.8
+
+Review important information about the {fleet} and {agent} 8.17.8 release.
+
+[discrete]
+[[new-features-8.17.8]]
+=== New features
+
+The 8.17.8 release adds the following new and notable features.
+
+Elastic Agent::
+
+* Add `Cumulativetodeltaprocessor` to EDOT Collector. {agent-pull}8372[#8372]
+
+[discrete]
+[[bug-fixes-8.17.8]]
+=== Bug fixes
+
+Elastic Agent::
+
+* Address a race condition that can occur in agent diagnostics if log rotation runs while logs are being zipped. {agent-pull}8215[#8215]
+* Use `paths.tempdir` for diagnostics actions. {agent-pull}8472[#8472]
+* Use Debian 11 to build linux/arm to match linux/amd64. Upgrades linux/arm64's statically linked glibc from 2.28 to 2.31. {agent-pull}8497[#8497]
+* Relax file ownership check to allow admin re-enrollment on Windows. {agent-pull}8503[#8503] {agent-issue}7794[#7794]
+
+// end 8.17.8 relnotes
+
 // begin 8.17.7 relnotes
 
 [[release-notes-8.17.7]]