[chore] Prepare release v1.56.0/v0.150.0 (#15101)

The following commands were run to prepare this release:
- make chlog-update VERSION=v1.56.0/v0.150.0
- make prepare-release PREVIOUS_VERSION=1[.]55[.]0
RELEASE_CANDIDATE=1.56.0 MODSET=stable
- make prepare-release PREVIOUS_VERSION=0[.]149[.]0
RELEASE_CANDIDATE=0.150.0 MODSET=beta

---------

Co-authored-by: otelbot <197425009+otelbot@users.noreply.github.com>

Author: otelbot[bot]

.chloggen/codeboten_semconv-140.yaml

@@ -7,6 +7,14 @@ If you are looking for user-facing changes, check out [CHANGELOG.md](./CHANGELOG
 
 <!-- next version -->
 
+## v1.56.0/v0.150.0
+
+### 💡 Enhancements 💡
+
+- `cmd/mdatagen`: Add custom validation support for Go config structs (#14563)
+
+<!-- previous-version -->
+
 ## v1.55.0/v0.149.0
 
 ### 💡 Enhancements 💡

.chloggen/debugexporter-profiles-guard-missing-dictionary-index.yaml

@@ -7,6 +7,27 @@ If you are looking for developer-facing changes, check out [CHANGELOG-API.md](./
 
 <!-- next version -->
 
+## v1.56.0/v0.150.0
+
+### 💡 Enhancements 💡
+
+- `all`: Update semconv package from 1.38.0 to 1.40.0 (#15095)
+- `cmd/mdatagen`: Only allow the `ToVersion` feature flag attribute to be set for the `Stable` and `Deprecated` stages. (#15040)
+  To better match the feature flag README
+  (https://github.com/open-telemetry/opentelemetry-collector/blob/main/featuregate/README.md#feature-lifecycle).
+  
+
+### 🧰 Bug fixes 🧰
+
+- `exporter/debug`: Guard from out of bounds profiles dictionary indices (#14803)
+- `pdata/pprofile`: create a copy when the input is marked as read-only (#15080)
+- `pkg/otelcol`: Fix missing default values in unredacted print-config command by introducing confmap.WithUnredacted MarshalOption. (#14750)
+  Resolves an issue where the unredacted mode output omitted all default-valued options. By introducing a new MarshalOption to disable redaction directly at the confmap encoding level, the unredacted mode now preserves all component defaults natively without requiring post-processing.
+  
+- `pkg/service`: Headers on the internal telemetry OTLP exporter are now redacted when the configuration is marshaled (#14756)
+
+<!-- previous-version -->
+
 ## v1.55.0/v0.149.0
 
 ### 🛑 Breaking changes 🛑

.chloggen/fix-unredacted-defaults.yaml

@@ -4,8 +4,8 @@ go 1.25.0
 
 require (
 	github.com/stretchr/testify v1.11.1
-	go.opentelemetry.io/collector/consumer v1.55.0
-	go.opentelemetry.io/collector/pdata v1.55.0
+	go.opentelemetry.io/collector/consumer v1.56.0
+	go.opentelemetry.io/collector/pdata v1.56.0
 	go.uber.org/goleak v1.3.0
 )
 
@@ -16,7 +16,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	go.opentelemetry.io/collector/featuregate v1.55.0 // indirect
+	go.opentelemetry.io/collector/featuregate v1.56.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )