Fix datetime theme color (#1111)

In Nushell 0.104.0, `date` are now `datetime` ([see
blog](https://www.nushell.sh/blog/2025-04-29-nushell_0_104_0.html#date-is-now-datetime-toc)).

I just change all `date` prop to `datetime` in all themes to fix them

Author: A1c0

themes/nu-themes/3024-day.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#cdab53' } else { '#fded02' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#db2d20' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/3024-night.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#cdab53' } else { '#fded02' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#db2d20' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/3024r.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#b5e4f4' } else { '#fded02' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#db2d20' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/abyss.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#2592d3' } else { '#1f6ca1' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#48697e' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/aci.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#1eff8e' } else { '#ff8308' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#ff0883' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/aco.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#1eff8e' } else { '#ff8308' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#ff0883' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/adventuretime.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#c8faf4' } else { '#e7741e' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#bd0013' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/afterglow.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#7dd6cf' } else { '#d3a04d' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#a53c23' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/alien-blood.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#00e0c4' } else { '#717f24' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#7f2b27' attr: 'b' }
             } else if $in < 6hr {

themes/nu-themes/alucard.nu

@@ -18,7 +18,7 @@ export def main [] {
 
         bool: {|| if $in { '#8ae9fc' } else { '#7f0a1f' } }
 
-        date: {|| (date now) - $in |
+        datetime: {|| (date now) - $in |
             if $in < 1hr {
                 { fg: '#ff5555' attr: 'b' }
             } else if $in < 6hr {