Fix panic in seq date (#11871)

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# Description
Fix #11732 

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# User-Facing Changes
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Invalid output format causes an error, not a panic.
```nu
❯ seq date --output-format '%H-%M-%S'
Error:   × Invalid output format
   ╭─[entry #1:1:1]
 1 │ seq date --output-format '%H-%M-%S'
   · ────┬───
   ·     ╰── an error occurred when formatting an argument
   ╰────
```
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crates/nu-command/src/generators/seq_date.rs

@@ -7,6 +7,7 @@ use nu_protocol::{
     Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Spanned,
     SyntaxShape, Type, Value,
 };
+use std::fmt::Write;
 
 #[derive(Clone)]
 pub struct SeqDate;
@@ -315,7 +316,19 @@ pub fn run_seq_dates(
 
     let mut ret = vec![];
     loop {
-        let date_string = &next.format(&out_format).to_string();
+        let mut date_string = String::new();
+        match write!(date_string, "{}", next.format(&out_format)) {
+            Ok(_) => {}
+            Err(e) => {
+                return Err(ShellError::GenericError {
+                    error: "Invalid output format".into(),
+                    msg: e.to_string(),
+                    span: Some(call_span),
+                    help: None,
+                    inner: vec![],
+                });
+            }
+        }
         ret.push(Value::string(date_string, call_span));
         next += Duration::days(step_size);
 

crates/nu-command/tests/commands/mod.rs

@@ -93,6 +93,7 @@ mod select;
 mod semicolon;
 mod seq;
 mod seq_char;
+mod seq_date;
 mod skip;
 mod sort;
 mod sort_by;

crates/nu-command/tests/commands/seq_date.rs

@@ -0,0 +1,8 @@
+use nu_test_support::nu;
+
+#[test]
+fn fails_when_output_format_contains_time() {
+    let actual = nu!("seq date --output-format '%H-%M-%S'");
+
+    assert!(actual.err.contains("Invalid output format"));
+}