fix(s3): add SSE-C parameters to headObject call

[ir0nhide]

This commit adds missing SSE-C Parameter to the headObject call used in the new S3 multipart upload feature.
Complementary to #38934.

Reference: https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadObject.html

[solracsf]

/backport to stable27

[juliusknorr]

Failure unrelated

[welcome]

Thanks for your first pull request and welcome to the community! Feel free to keep them coming! If you are looking for issues to tackle then have a look at this selection: https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22

[juliusknorr]

/backport to stable27

[backportbot-nextcloud]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27

# Create the new backport branch
git checkout -b fix/foo-stable27

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable27

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[backportbot-nextcloud]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27

# Create the new backport branch
git checkout -b fix/foo-stable27

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable27

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport