chore: collapse the ifs the 1.98 clippy flags

The pinned toolchain's clippy grew opinions the older lint let stand:
nested if/if-let pairs it wants as let-chains, and a modulo test it
wants as is_multiple_of. Machine-applied collapses, fmt-settled, no
behavior change — the gauntlet runs clean again.

integrations/rhema-calendar-integration/src/ics.rs

@@ -234,18 +234,18 @@ fn vevent_blocks(raw: &str) -> Vec<Vec<ContentLine>> {
             }
             "END" => {
                 let component = line.value.trim().to_ascii_uppercase();
-                if component == "VEVENT" {
-                    if let Some(block) = current.take() {
-                        blocks.push(block);
-                    }
+                if component == "VEVENT"
+                    && let Some(block) = current.take()
+                {
+                    blocks.push(block);
                 }
                 stack.pop();
             }
             _ => {
-                if stack.last().map(String::as_str) == Some("VEVENT") {
-                    if let Some(block) = current.as_mut() {
-                        block.push(line);
-                    }
+                if stack.last().map(String::as_str) == Some("VEVENT")
+                    && let Some(block) = current.as_mut()
+                {
+                    block.push(line);
                 }
             }
         }
@@ -755,10 +755,10 @@ fn expand_rule(
         if walked > MAX_CANDIDATES {
             return false;
         }
-        if let Some(until) = rule.until {
-            if start > until {
-                return false;
-            }
+        if let Some(until) = rule.until
+            && start > until
+        {
+            return false;
         }
         if start > window.to {
             return false;

integrations/rhema-forge-integration/src/gitea.rs

@@ -398,10 +398,10 @@ fn review_event(
         Some(timestamp) => timestamp,
         None => return Ok(None),
     };
-    if let Some(since) = since {
-        if timestamp < *since {
-            return Ok(None);
-        }
+    if let Some(since) = since
+        && timestamp < *since
+    {
+        return Ok(None);
     }
     let id = required(row.id, "review id")?;
     Ok(Some(ForgeEvent {
@@ -577,10 +577,10 @@ impl Forge for GiteaForge {
         ];
         for row in self.paged::<WirePull>(&pulls_path, &query).await? {
             let updated = required(row.updated_at.clone(), "pull updated_at")?;
-            if let Some(since) = since {
-                if updated < *since {
-                    continue;
-                }
+            if let Some(since) = since
+                && updated < *since
+            {
+                continue;
             }
             let number = required(row.number, "pull number")?;
             if let Some(event) = pull_event(&row, repo)? {

integrations/rhema-forge-integration/src/github.rs

@@ -400,10 +400,10 @@ fn review_event(
     }
     // A review without a submission time was never submitted.
     let timestamp = required(row.submitted_at.clone(), "review submitted_at")?;
-    if let Some(since) = since {
-        if timestamp < *since {
-            return Ok(None);
-        }
+    if let Some(since) = since
+        && timestamp < *since
+    {
+        return Ok(None);
     }
     let id = required(row.id, "review id")?;
     Ok(Some(ForgeEvent {

integrations/rhema-forge-integration/src/gitlab.rs

@@ -382,10 +382,10 @@ fn note_event(
         return Ok(None);
     }
     let timestamp = required(row.created_at.clone(), "note created_at")?;
-    if let Some(since) = since {
-        if timestamp < *since {
-            return Ok(None);
-        }
+    if let Some(since) = since
+        && timestamp < *since
+    {
+        return Ok(None);
     }
     let id = required(row.id, "note id")?;
     Ok(Some(ForgeEvent {