Refactor timestamp formatting in Git UI components to use chrono for local time calculations (#41005)

- Updated `blame_ui.rs`, `branch_picker.rs`, `commit_tooltip.rs`, and
`commit_view.rs` to replace the previous timestamp formatting with
`chrono` for better accuracy in local time representation.
- Introduced `chrono::Local::now().offset().local_minus_utc()` to obtain
the local offset for timestamp formatting.

Closes #40878

Release Notes:
- Improved timestamp handling in various Git UI components for enhanced
user experience.

crates/git_ui/src/commit_tooltip.rs

@@ -14,7 +14,6 @@ use settings::Settings;
 use std::hash::Hash;
 use theme::ThemeSettings;
 use time::{OffsetDateTime, UtcOffset};
-use time_format::format_local_timestamp;
 use ui::{Avatar, Divider, IconButtonShape, prelude::*, tooltip_container};
 use workspace::Workspace;
 
@@ -190,9 +189,11 @@ impl Render for CommitTooltip {
             .map(|sha| sha.to_string().into())
             .unwrap_or_else(|| self.commit.sha.clone());
         let full_sha = self.commit.sha.to_string();
-        let absolute_timestamp = format_local_timestamp(
+        let local_offset = UtcOffset::current_local_offset().unwrap_or(UtcOffset::UTC);
+        let absolute_timestamp = time_format::format_localized_timestamp(
             self.commit.commit_time,
             OffsetDateTime::now_utc(),
+            local_offset,
             time_format::TimestampFormat::MediumAbsolute,
         );
         let markdown_style = {
@@ -351,11 +352,11 @@ impl Render for CommitTooltip {
 fn blame_entry_timestamp(blame_entry: &BlameEntry, format: time_format::TimestampFormat) -> String {
     match blame_entry.author_offset_date_time() {
         Ok(timestamp) => {
-            let local = chrono::Local::now().offset().local_minus_utc();
+            let local_offset = UtcOffset::current_local_offset().unwrap_or(UtcOffset::UTC);
             time_format::format_localized_timestamp(
                 timestamp,
                 time::OffsetDateTime::now_utc(),
-                UtcOffset::from_whole_seconds(local).unwrap(),
+                local_offset,
                 format,
             )
         }