CHANGELOG generator fixes (#8334)

- adds the newly introduced GUCs
- fixes the links from the .unlreleased files

Disable-check: approval-count
Disable-check: force-changelog-file

Author: philkra

scripts/changelog/generate.sh

@@ -9,16 +9,27 @@ echo_changelog() {
     echo "${1}"
     # skip the template and release notes files
     grep -i "${2}" .unreleased/* | \
-        cut -d: -f3- | sort | uniq | sed -e 's/^[[:space:]]*//' -e 's/^/* /' -e 's!#\([0-9]\+\)![#\1](https://github.com/timescale/timescaledb/pull/\1)!'
+        cut -d: -f3- | sort | uniq | sed -e 's/^[[:space:]]*//' -e 's/^/* /' -e 's!#\([0-9][0-9]*\)![#\1](https://github.com/timescale/timescaledb/pull/\1)!g'
     echo
 }
 
+# Build a delta of the GUCs between two releases
+#
+# Param: previous release
+# Param: release branch
+#
+echo_gucs() {
+    echo "**GUCs**"
+    git diff ${1}..${2} src/guc.c | grep EXTOPTION | grep -o '"[^"]*"' | sed 's/^/* /' | sort | sed 's/"/`/g'
+}
+
 get_version_config_var() {
     grep "${1}" version.config | awk '{print $3}' | sed 's/-dev//'
 }
 
 RELEASE_NEXT=$(get_version_config_var '^version')
 RELEASE_PREVIOUS=$(get_version_config_var '^previous_version')
+RELEASE_BRANCH="${RELEASE_NEXT/%.[0-9]/.x}"
 
 echo "Building CHANGELOG"
 {
@@ -31,8 +42,7 @@ echo "Building CHANGELOG"
     echo ""
     echo_changelog '**Features**' '^Implements:'
     echo_changelog '**Bugfixes**' '^Fixes:'
-    echo "**GUCs**"
-    echo "* "
+    echo_gucs $RELEASE_PREVIOUS $RELEASE_BRANCH
     echo "" 
     echo_changelog '**Thanks**' '^Thanks:' 
 } > CHANGELOG_next.md

scripts/release/build_post_release_artefacts.sh

@@ -47,7 +47,7 @@ curl --silent --fail -o CHANGELOG.md $URL_CHANGELOG
 
 # .unreleased files
 echo "remove .unreleased files"
-echo "TODO"
+git diff ${PUBLISHED_VERSION}..main .unreleased/* | xargs rm -fv
 
 # Set new previous version
 echo "Set new previous version version.config to ${PUBLISHED_VERSION}"