make: Fix circular dependency warning

[jef-n]

These from https://github.com/OSGeo/grass/commit/69250e7096fb473b8abab795e95bb1b84a0a6494/checks/22431574413/logs:

$ zgrep Circular logs_21518779849.zip | tee >(head -10 >/dev/tty) | wc -l
2024-03-08T10:25:12.8032190Z make[4]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:25:13.2727731Z make[3]: Circular ../mswindows/generic.manifest.rc <- ../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:27:22.8816153Z make[6]: Circular ../../../mswindows/generic.manifest.rc <- ../../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:18.1297727Z make[4]: Circular ../../../mswindows/generic.manifest.rc <- ../../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:26.9007408Z make[4]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:27.2913475Z make[4]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:27.6679747Z make[4]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:28.0431812Z make[4]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:29.3249221Z make[4]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
2024-03-08T10:28:34.3177967Z make[5]: Circular ../../mswindows/generic.manifest.rc <- ../../mswindows/generic.manifest.rc dependency dropped.
163

[echoix]

I understand both of the changes. They seem to be correct to me. An input file was renamed to .in since it is modified during build, and the file name is taken from the list of prerequisites from $^. I rely on your expertise to know that it is the correct thing to do, so combining the two, this PR is ok to merge!

[echoix]

@neteler is this something backportable?

[neteler]

@neteler is this something backportable?

Yes, backported to 8.3.

Thanks @jef-n !