tests: add spdx license header to test unit/link/network/conf files

Those are all consumed by our parser, so they all support comments.
I was considering whether they should have a license header at all,
but in the end I decided to add it because those files are often created
by copying parts of real unit files. And if the real ones have a license,
then those might as well. It's easier to add it than to make an exception.

test/test-sysusers/test-1.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Trivial smoke test that covers the most basic functionality
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-10.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # check that 'm' lines do not conflicts 'u' line
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-11.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 #Type Name ID  GECOS HOMEDIR
 u     u1   222 -     -
 g     g1   111 -     -

test/test-sysusers/test-12.input

@@ -1 +1,2 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 u systemd-coredump  1 "systemd Core Dumper"

test/test-sysusers/test-13.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure that the semantic for the uid:groupname syntax is correct
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-14.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure that a preexisting system group can be used as primary
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-2.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Test generation of ID dynamically based on SYSTEM_UGID_MAX and
 # replacement of all fields up to the login shell.
 #

test/test-sysusers/test-3.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure that the semantic for the uid:gid syntax is correct
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-4.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure that already created groups are used when using the uid:gid syntax
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-5.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Reproduce the base-passwd master.{passwd,group} from Debian
 #
 #Type  Name        ID GECOS Home directory

test/test-sysusers/test-6.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure that existing IDs are not reused by default. I.e. the existing
 # ID 111 from g1 will cause u1 to get a new and different ID (999 on most
 # systems).

test/test-sysusers/test-7.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Issue #8315
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/test-8.input

@@ -1,2 +1,3 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 g groupname 300
 u username -:300

test/test-sysusers/test-9.input

@@ -1,2 +1,3 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 u user1 300
 u user2 -:300

test/test-sysusers/unhappy-1.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure invalid uids are detected
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/unhappy-2.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure it is not allowed to create groups implicitly in the uid:gid syntax
 #
 #Type Name ID  GECOS HOMEDIR

test/test-sysusers/unhappy-3.input

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Ensure it is not allowed to create groups implicitly in the uid:groupname syntax
 #
 #Type Name ID  GECOS HOMEDIR