tests/fixtures/packages/overlays: use debhelper level 12

The additional packages below `overlays` were overlooked when
49a2b800 switched the test packages to
a non-deprecated debhelper compat level.

tests/fixtures/packages/overlays/binnmu/debian/compat

-9

tests/fixtures/packages/overlays/binnmu/debian/control

@@ -3,7 +3,7 @@ Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
 Uploaders: An Uploader <uploader@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper-compat (= 12)
 Rules-Requires-Root: no
 
 Package: binnmupkg

tests/fixtures/packages/overlays/main-contrib-with-debug/debian/compat

-9

tests/fixtures/packages/overlays/main-contrib-with-debug/debian/control

@@ -2,7 +2,7 @@ Source: main-contrib-with-debug
 Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper-compat (= 12)
 Rules-Requires-Root: no
 
 Package: main-package

tests/fixtures/packages/overlays/package/debian/compat

-9

tests/fixtures/packages/overlays/package/debian/control

@@ -3,7 +3,7 @@ Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
 Uploaders: An Uploader <uploader@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper-compat (= 12)
 Rules-Requires-Root: no
 
 Package: package

tests/fixtures/packages/overlays/pkgnew-0.1/debian/control

@@ -3,7 +3,7 @@ Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
 Uploaders: An Uploader <uploader@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper (= 12)
 Rules-Requires-Root: no
 
 Package: pkg-all1

tests/fixtures/packages/overlays/pkgnew-0.2/debian/control

@@ -3,7 +3,7 @@ Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
 Uploaders: An Uploader <uploader@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper-compat (= 12)
 Rules-Requires-Root: no
 
 Package: pkg-all1

tests/fixtures/packages/overlays/pkgnew-0.2~exp/debian/control

@@ -3,7 +3,7 @@ Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
 Uploaders: An Uploader <uploader@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper-compat (= 12)
 Rules-Requires-Root: no
 
 Package: pkg-all1

tests/fixtures/packages/overlays/pkgnew-0.3/debian/control

@@ -3,7 +3,7 @@ Section: misc
 Priority: extra
 Maintainer: A Maintainer <maint@example.com>
 Uploaders: An Uploader <uploader@example.com>
-Build-Depends: debhelper (>= 9)
+Build-Depends: debhelper-compat (= 12)
 Rules-Requires-Root: no
 
 Package: pkg-all1

tests/fixtures/packages/overlays/pkgnew/debian/compat

-9