chore: bump version

[rajyan]

Issue #, if available:

closes #93
closes #83
closes #76
closes #57

as mentioned in the above issues, VERSION is fixed at 1.2.0.0 causing the session-manager-plugin to exit after 30 seconds. (ref: #83 (comment)) This behavior makes the plugin unusable when using it as a library from other tools.

Additionally, the README does not mention the need to edit the VERSION, which results in non-functional binaries when built from the source code. In fact, a non-working version is bundled with Alpine.

$ docker run --rm -it alpine
/ # apk add aws-session-manager-plugin
fetch https://dl-cdn.alpinelinux.org/alpine/v3.21/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.21/community/x86_64/APKINDEX.tar.gz
(1/64) Installing libbz2 (1.0.8-r6)
...
(64/64) Installing aws-session-manager-plugin (1.2.694.0-r0)
Executing busybox-1.37.0-r9.trigger
OK: 319 MiB in 79 packages
/ # session-manager-plugin --version
1.2.0.0

Description of changes:

This PR resolves the issue by specifying the version.
I have confirmed that binaries built with this version work as expected.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[rajyan]

@Yangtao-Hua

Hello, this PR addresses many long-standing issues. I would greatly appreciate it if you could take a look!

[djselzlein]

Hello @rajyan !
This fix has resolved #83 issue for me. Thank you so much!